Questions on: Lilacs
Ron Smith, Horticulturist, NDSU Extension Service
Q: When is the best time to trim our lilacs so we don't affect their flowering next year? (e-mail reference)
A: Right after they finish flowering this year!
Q: My wife and I planted a lilac on Mother's Day four year ago. There were plenty of flowers the first year, but less and less each year since. There was only one flower this year. I was told to add lime to the dirt around the plant and add 10-10-10 fertilizer. I did this, but I still do not have any new flowers. I have two questions. Some of the leaves on the plant seem to be getting small holes in them. How do I prevent this from spreading? Also, how do I get it to flower again? (e-mail reference)
A: The lack of flowering could be from overfertilization, improper pruning or too much shade. Flower buds for the next season are formed during the previous summer. In other words, the flower buds will form or not for 2008 sometime this summer, depending on whatever pruning is done or anything else that might prevent bud formation. As to the holes in the leaves, you can spray with Malathion to prevent any future eating, but I doubt that the action is worth it. Usually, when the damage is observed, the insect pest already is gone.
Q: I want to plant a hedge of common or Chinese lilacs. How far apart should I plant them? There is landscape fabric and rock where I want to plant. Do I need to remove the rock and fabric? Also, this spot is next to a hay field. How far from the field should I plant so the plants won't grow into the irrigation pipe? Is there a preference between common or Chinese lilacs for a hedge? (e-mail reference)
A: For a more sophisticated-looking hedge, go for the Chinese lilac. It is a hybrid of the common and Persian lilac. It gets anywhere from 8 to 15 feet tall and as wide. You have to remove the fabric and stone before planting. As for the distance away from the irrigation pipe, my guess would be about 20 feet. Spacing is up to you, depending on how quickly you want a solid hedge.
Q: While driving near the Green River in Stark County, I noticed some tall, thick shrubs with white flowers. Upon closer inspection, I believe they are Japanese lilacs. We live near that area, so I believe the soil type would be similar to ours. Are you aware of any local nursery that carries them? Is there any negative aspect to planting these as a decorative hedge/windbreak in a rural setting? (Gladstone, N.D.)
A: I can think of nothing negative about these plants in the setting you describe. As for any nursery that might be selling them, I can't help you there. Call around in Dickinson or Bismarck to see if there are any available.
Q: My husband sprayed my lilac hedge for weeds while I was on vacation. Now one of the lilacs is wilted. I have been watering it to see if it will come back. It has been two weeks now and it does not look good. The rest of the lilacs look OK. The hedge has river rock along the base, so he wanted to kill the grass that is growing on the rocks. What would be the preferred product to use to kill the grass and not my lilacs? Please help my husband get out of the doghouse! (e-mail reference)
A: Next time, take your husband on vacation with you so this won't happen again! Roundup would be a good choice for any kind of vegetation control in the setting you described. If he wanted to control just the grassy growth, he should get a grass killer that has sethoxydim as the active ingredient. If he should misapply the product, it won't harm your lilacs. The lilac that has been affected probably will recover eventually. Don't water too much because that may kill the lilacs quicker than the herbicide. Since your husband is occupying the doghouse, has the family dog now been given the run of the family home?
Q: I have a lilac tree that always has been purple. Last year I noticed it was all purple, but had two white flowers. Now the entire tree is covered with white flowers. What happened? How can I change it to a deeper, darker purple? (e-mail reference)
A: No idea. All I can guess is that the purple scion wood flowers were grafted onto white rootstock. Sorry. If anybody comes up with an answer, I'll let you and everyone else know!
Q: I live in central Scotland. My grandma moved here from the Scottish Highlands in the 1950s. She brought with her a cutting from her mother's lilac bush and planted it in her garden. It flowered beautifully until about 15 years ago. Unfortunately, my grandma passed away last year. In her memory, I would like to grow a lilac bush in my garden from a cutting taken from her lilac. Will it grow even though the original bush has not flowered in years? What is the best way to go about growing it? Thanks and best wishes! (e-mail reference)
A: Lilac cuttings easily root if taken in mid-June. The cuttings should be 8 to 10 inches long. Dip the cuttings in a rooting hormone and then stick them in a sand medium under mist. Lilacs characteristically develop a nice mass of roots.
Q: I bought a house with three large lilac bushes in back. The three are white, purple and reddish purple in color. They are beautiful, but I have severe allergies and asthma and believe they are aggravating my problems. How long do the blooms last? Can I remove them now? Can I prevent the blooms from coming back and still keep the bushes? (Denver, Colo.)
A: You can remove them now, with no harm to the plants. To keep them from blooming every spring, do an early spring pruning while the plants are dormant. If you do this, you will not get blooms that year.
Q: I adore the fragrance of lilacs and hyacinth. I had lilacs on the side of our house in Indiana as a child. I now live in San Diego. I am in a condo with front and back patios. However, my patios are not at ground level, so I need to grow plants in a pot. Can these flowers grow in that format and will they do well in Southern California? I never see them growing around here, especially lilacs. (e-mail reference)
A: Sorry, you are out of luck. Lilacs and hyacinths need cold treatments from Mother Nature to grow and produce flowers. You could move to North Dakota, where we occasionally have cold weather that brings the lilacs and hyacinths into flower!
Q: I have a lilac bush and need to know when and how to take cuttings. (e-mail reference)
A: When you use the term cuttings, I take it to mean that you want to carry out propagation. If that is the case, you should know that lilacs are not easily rooted from cuttings, so timing is very critical. Softwood cuttings work best and should be taken before the leaves mature. The cuttings will need to be treated with a rooting hormone and placed in a sand or vermiculite medium. For watering, use an intermittent misting system. If you are talking about just pruning the plants, there are a couple of options. If you prune while the bush is dormant, you have to realize that each stem you remove will reduce the number of spring blooms. The other option is to wait until blooming has ended, then do the pruning before new growth emerges and has a chance to set flower buds for the following spring.
Q: We planted a row of lilac bushes that were looking good until they were attacked by pocket gophers. The gophers made a maze of mounds and began chewing their way through the roots just beneath the soil surface. The lilacs fell over and died because the roots were severed. We now have pocket gophers moving into our strawberry bed. What can we do to control these destructive pests? (Henry, S.D.)
A: I strongly suggest you hire a professional exterminator to do the job. One or two events are something the homeowner can control, but with the invasion you describe, you need professional help. Traps would be inadequate in this instance.
Q: I have a lilac bush that has leaf rollers on the leaves. How do I get rid of them without hurting the lilac bush and the environment? When is the best time to do it? (e-mail reference)
A: The best time is when the pests are actively feeding. For control, use Bayer Advanced Tree and Shrub Insect Control. It is a systemic that is picked up by the roots and translocated throughout the plant. It lasts for up to 12 months. Be sure to follow label directions.
Q: Two weeks ago, a very large tree came down and landed on a row of mature lilac bushes. Will the lilac bushes survive? When removing the fallen tree, what care should be given to the lilac bushes? If they survive, I would like to transplant them about 20 miles from where they are now. The new area has more sandy soil. What care should I take to transplant the bushes? What is the best time of year to transplant? (e-mail reference)
A: Please go to my site on lilacs at www.ext.nodak.edu/extnews/hortiscope/shrub/lilac.htm. Normal care should be exercised when removing the tree from the lilacs. They likely will survive.
Q: We have a lilac tree that just started to grow and bloom this year, but it seems we have carpenter ants in the tree. The ants have cut a groove into the base of the tree. I would love to get rid of them before they destroy our beloved tree. It appears that the tree is extruding sap. Could this be why the ants are attacking the tree? It also seems we have attracted yellowjackets. Any suggestions? (e-mail reference)
A: It sounds like you have borers causing the sap to flow from the branches. You also may have an aphid infestation that is causing the sappy dripping. Ants will use the aphids in the same way we use cows for milking, except the ants collect the honeydew the aphids excrete through their bodies as a result of their feeding. This same material interests the yellowjackets. Examine the plant to see if aphids or any other insect that has a piercing-sucking mouth part, such as scale, are present on the stems and leaves. Examine the stems as well to see if there are specific sites where the sap is being exuded. This would indicate the possible presence of a lilac borer. If you don't have the confidence to make these judgments, contact a tree, shrub or landscape service to do it for you. It would be a good idea to control the yellowjackets using traps rather than sprays. Their stings not only hurt, but can be toxic to certain individuals.
Q: We need to move a large, beautiful lilac bush. When is the best time to relocate the bush? What's the best method? (e-mail reference)
A: The best time is early spring while the bush is dormant. The next best time is in the fall after the leaves have dropped. The worst time is now. If the shrub is accessible, a small-scale tree spade probably would do the best job because it would be able to encompass the largest mass of roots for moving. Otherwise, it would be too big to be moved by hand because too much of the root system would have to be left behind.
Q: I regularly read your tips in the paper and find them very helpful. I have two problems I am hoping you can help me with. I have a lilac tree that bloomed the first two years, but not this year. Also, my cotoneaster hedge has grown too tall. I am wondering if it could be trimmed back about 12 inches. If so, when is the best time to trim? (Moorhead, Minn.)
A: If you trimmed the lilac after mid-July last year, that could be the reason why the lilac didn't bloom this year. For the cotoneaster, you can prune at this time of year, but the best time is while it is dormant in the spring.
Q: We planted a lilac and a climbing rose two years ago. They both look healthy, but haven’t produced any blooms. What is the time frame for flowers to bloom? I was reading about pruning lilacs in the spring after blooming. If there are no blooms, when should we prune? Should I be cutting back the climbing rose so it will climb? I fertilize the rose with Miracle-Gro. Should I use another product? (e-mail reference)
A: If the plants are in full sun and not overfertilized, then they should bloom. Try driving a spade into the soil around the base of the plants to cut off some of the roots, but not all. This will cause the plants to be shocked into flowering the following season, at least the lilacs. Roses bloom on the current season's growth, so you might get a reaction this growing season.
Q: I purchased some lilac plants this weekend. Five are blue and two are white. I planted them about 2 1/2 feet apart. Is that far enough apart? I planted them to make a divider between my yard and that of my neighbors. My neighbors are very happy to have lilacs. I am, too, but I don't want them to look sloppy when they grow. (e-mail reference)
A: Two and half feet apart is a little too close because (assuming they are the common lilac) they can spread out to 8 or more feet. You might want to take out every other plant and transplant them somewhere else. You could leave the plants in place, but remove every other plant when they start to become crowded.
Q: I enjoyed reading your Hortiscope articles very much. The column is a great resource for a beginning gardener, especially the information on lilacs. I now know I'm not alone in almost killing these tough beauties. I have two Miss Kim lilacs that were planted in the wrong location last spring. The soil was heavy clay with poor drainage. We installed a French drain along the bed and hoped that would help. The plants struggled for most of last year, with shriveled leaves on almost bare branches. Several of the branches died. I pruned the rest of the branches down to 3-inch stumps last fall. This spring, the lilacs put out nice green leaves, bloomed for a few days and promptly turned brown! When I checked two weeks ago, there was a puddle of standing water in the planting hole. My guess is the lilacs were drowning after extensive spring rains, so I moved them to another spot and planted them on a raised mound. Since the lilacs were recently moved, should I heavily prune the plants to rejuvenate growth? The plants do not have leaves, but the branches have some green under the bark. With all that has happened to these lilacs, can they survive? (e-mail reference)
A: The plants are reacting to the trauma of being moved and flooded. As long as the cambium is still green beneath the bark, there is a chance for recovery. Don't overwater or prune anything and certainly don't fertilize. If the plants are going to recover, they will with normal care.
Q: We share a 20-year-old lilac bush on our property line with our neighbor. For more privacy, our neighbor has tied a few of the branches near the top of the bush down to the ground so the branches are bowed over. I am concerned that the bending pressure is going to stress the plant. Will this kill the plant or prevent blooming? Thanks for your help. (e-mail reference)
A: The only major stress would be the material the neighbor tied to the branches. The neighbor or you need to keep an eye on the bush to make sure that it doesn't start to girdle or chaff the bark on the branches. I suggest that the two of you go shopping for another lilac to fill that spot. It must look weird to see the shrub bent over. The aesthetics of another plant would complement both properties.
Q: I am cutting lilacs for my wedding and need to know where on the branch to cut. I do not want to damage the tree or discourage it from blooming in the future. (e-mail reference)
A: Cut it anywhere you wish in order to get the flowers. The lilac will send out new growth after the blooms fade and then set new flower buds for next year. Get the cutting done as soon as possible.
Q: About four years ago, I received a lilac bush from my mother-in-law for Mother's Day. The lilac keeps getting better and better, but it has yet to bloom. Each year it gets a little taller and has more and more green leaves on it. I've never done anything to it since it was planted. Should it be pruned? Please help. I'm terrible with plants, but I really want to get better because we're finally landscaping around the new house we built. That leads me to my hydrangeas. I purchased two forever pink and one PG hydrangea that I want to plant in one area and five Sister Theresa hydrangeas to be planted somewhere else. How far apart should I plant them? Any tips would be appreciated. When will they start to bloom? (e-mail reference)
A: The lilac may not be blooming because it is getting too much shade or nitrogen-rich fertilizer. You might be able to stimulate it to set flower buds by driving a straightedge spade into the ground around the edge of the spread of the foliage. Do that in about six places. This mildly shocks the plant into a reproductive cycle. I would suggest planting the hydrangeas about three to four feet apart. They are among the easiest plants on earth to grow. Plant them at the right depth, keep them watered, but not soggy, and they should bloom for you.
Q: My friend has a miniature Japanese lilac tree that has a 6-foot tall sucker. Is it possible to cut the sucker near the soil and replant it somewhere else? (e-mail reference)
A: Yes, as long as it isn't going to flower. Do it going into the evening hours, give it plenty of water and give it a dash of soluble fertilizer.
Q: I have a question about my lilac bush. It appears that my neighbor’s cat has clawed the bark at the bottom of the bush. On some branches, it goes all the way around the stem. I am hoping this will not kill the plant. Do you think I could prune it back in the fall with the hopes of saving it? (e-mail reference)
A: Established lilacs are tough plants, so yours should survive the clawing. You likely will get some new growth coming out of the crown, which you can then manage the way you want. Cut out the girdled stems because they are dead, even if they leaf out this summer. After that, get some Liquid Fence and spray it around the bush to keep the cat away. This stuff doesn't smell nice, so it should keep the cat and any other mischief-makers away from your plants.
Q: I have a question about cutting lilacs from a bush and putting them in a vase. What is the best way to help them last longer? Do I need to put anything in the water? I have a lilac bush and tulips that I put in the same vase because the flowers make my house smell great, but I want to know what would make the flowers last longer. (e-mail reference)
A: Go to a florist and ask for a packet of flower extender. The florist will give it to you or charge a small fee. Changing the water every day also will extend the life of the flowers. Moving them to a dark, cool location at the end of the day also works well.
Q: I have a lilac bush. It has bloomed every year, with the number of flowers increasing each year. The leaves start coming out around this time, but this year there are no leaves appearing. The limbs are flexible and do not snap off when bent. Could it be dormant or is it dead? (e-mail reference)
A: Check the cambium under the bark. If it is still green, then it probably will leaf out. If it is not green, then it could be dead. I would suggest being patient. Mother Nature doesn't always follow the exact same schedule. Temperature fluctuation, extended cold weather or frozen ground all have a bearing on the growth cycle of any plant.
Q: Last year I planted a lilac purchased from a reputable nursery. By the end of the summer, every branch was dead except one. I cut the dead branches off, leaving about 5 inches on each. The one branch that survived is now covered with buds and more than 5 feet tall. I had hoped I would see some new growth around the stump, but there doesn't appear to be any. I was hoping to eventually have a large, bushy, healthy lilac. I also have golden privet that was extremely healthy and happy until I moved it last spring. I only moved it about 4 feet. I did move it closer to my cement foundation. It was not nearly as lush as the previous summer. I was generous with using Miracle-Gro. (e-mail reference)
A: After the lilac flowers this spring, cut it back to a leaf node to force it to bush out. As for the privet, it doesn't make a difference how far you move it. The privet will “pout” for a while. Continue with the Miracle-Gro treatments once a month during the active growing season.
Q: We have lilac bushes that rabbits have stripped the bark off up to a foot above the ground. These are established bushes. Should we cut back the chewed parts? Will the lilacs bloom again this year? When should they be trimmed? (e-mail reference)
A: If the rabbits have completely girdled the stem, the stem is dead and likely will not have enough energy to flower. I would suggest leaving everything as it is to see what happens. The plants may leaf out with undersized leaves and reduced flowers and then suddenly die. There is a possibility there will be no foliage or flowers this year. In either case, cut the bushes below the damaged area and you probably will get a flush of growth coming from the crown. The flush will come whether or not you trim the damaged shoots back, but they will not flower until next spring. Since you are bothered by rabbits, I would suggest that you use one or a combination of Liquid Fence, Plantskydd or Hinder.
Q: This weekend our boys had over some friends who have a snowmobile. The boys ran over one of my lilac bushes. It snapped off at the base of the plant. Can the bush be rerooted? The roots are still in the ground. Will a new bush start to grow? Any information you can give me would be great. (e-mail reference)
A: Most likely, no serious harm was done, so you can let them out of the dungeon. Plants probably will sprout from the roots, but will not flower this year. The plants should flower next year, assuming the boys don't do the same thing again!
Q: I have a miniature lilac bush in front of my porch. It is bare on the side of the porch. I would like to cut it down so it would renew itself. My neighbor told me to cut it down in March. She mentioned it would come back without the bare spot. I'm just not sure how far back I'm supposed to cut it. I don't want to kill it. (e-mail reference)
A: In this case, your neighbor is correct. Cut the bush back to short stubs (about 6 inches long) and you should get a flush of new growth this spring, but the plant will not bloom. That will happen next year.
Q: How can I tell whether the lilac starts I have are from trees or bushes? Some of these starts were from shoots around a tree and others are from old bushes that were neglected and overgrown. Can I prune a bush into a tree by cutting the shoots at ground level or is this a bush that should remain a bush? (e-mail reference)
A: Common lilacs are considered large shrubs, but sometimes are referred to as small trees. It depends on how the lilacs are pruned. Generally, the more common parlance is a large shrub. Either way, the flowers are beautiful and fragrant!
Q: We will start building a new house as soon as the ground dries. We received new, small lilac plants (really root balls the size of a fist) as a gift. Can we plant them in pots until we know exactly where we want them or are we better off making our best guess and hoping they aren't disturbed during the construction process? (e-mail reference)
A: Move them to containers and keep them as far away from the construction process as possible!
Q: I found your Web site and was so happy to see that you might be able to help me. I have a lilac tree growing in my backyard. It flowers beautifully, but the flowering is brief. Is that common? I want to move the tree because it blocks access to the yard. Can I do that or should I try to take a cutting and root it as you say on your Web site? If I do the cutting and replant, how long will it take the tree to grow and flower? I must admit I do not have a green thumb, but I'd really like to save the tree because I enjoy it so much. (e-mail reference)
A: Lilacs that size do not enjoy being moved, so you are better off attempting to propagate it or taking the easier route by purchasing another lilac. I suggest the latter since you admit to not having a green thumb. The length of bloom of most spring flowering shrubs is usually dictated by the weather. If it is cool and breezy, the blooms will last longer. If it is hot and windy, the blooms won’t last as long.
Q: I have two lilac trees. I need to move them because the garage is being expanded. What is the best way to dig them up? Do I cut the branches down to the ground and then dig them up or do I trim off the big branches. My husband wants to dig around them and then use a rope to pull them out. I don't think this a good idea, but I need suggestions to convince him not to fire up the truck. Help! (e-mail reference)
A: The technique intended by your husband will just about insure the trees won’t survive. The best way to move them, from the lilac's point of view, is to have them surgically dug out with a tree spade. The operator can come in with a small spade and make about a 36-inch rootball. The operator can move an entire tree in a matter of minutes with a very high chance the tree will survive. Some selective pruning will be needed. Take out the oldest canes back to ground level.
The next best idea is to dig a trench around the plants to make a 36-inch rootball. With a sharpshooter spade, cut the fleshy roots as cleanly as possible. Having the new planting holes already dug is strongly encouraged. With a burlap cloth worked under the roots, slide or tote the plants to the new site. Be sure the trees are planted at the same depth as before. Drop the tree into the hole with the burlap because the burlap will rot. Prune the same as with the tree spade and then water. The popular technique of a chain around the base and attached to the bumper hitch will result in a lot of damage to the turf and the plants being yanked out of the ground. If that is the only acceptable alternative, you might as well write them off and plant new ones.
Q: I recently bought an old farm with some big lilac bushes close to the house. We want to put a porch on the house, but the bushes are in the way. I don't want to kill them because I enjoy lilacs. Is there a way to move them with a spade? Thanks for the help. (e-mail reference)
A: Lilacs move and survive easily, if they are moved when dormant. Try to move as much of the root system as possible.
Q: I have a friend who wants to plant lilac bushes. I told her she could have clippings from mine. I have looked at different Web sites and books for information. Some say to dig up the suckers and others say to get leaf or stem clippings. The bushes in my yard have white decorative stone around them for drainage and weed prevention. My bushes are very healthy and I’ve had them for more than 40 years. What would be the best way for me to give my friend some of my bushes without damaging the plants? (e-mail reference)
A: Generally, softwood cuttings will work best with a dip of the ends into a rooting hormone, such as IBA. Place them in a well-drained medium of coarse, clean sand. Keep the plants misted or kept in the shade and hand misted during the day. Go to www.ext.nodak.edu/extpubs/plantsci/landscap/h1257.pdf to download information on propagation techniques.
Q: We planted a 150-foot row of bare-root common lilac along the sidewalk on the back of our lot. We hoped it would grow to be a hedge and provide some privacy. Eight years later, the tallest lilac is about 4 1/2 feet tall, but many are less than 2 feet. They have bloomed every year since the first spring after we planted them. The soil is regular Red River Valley clay and the lilacs are not in a low spot. I've tried watering, pruning and fertilizing, but nothing seems to make the plants grow faster. After eight years, we thought we would be pruning them regularly to keep them at about 8 feet. I have thought of sending in soil samples, mulching or using more fertilizer. Is it possible there was a mix up at the nursery and these are some sort of miniature lilacs? (Fargo, N.D.)
A: Very much so! If you can send a sample of a branch with buds on it to my attention at the NDSU Department of Plants Sciences, Box 5051, Fargo, ND 58105, we will attempt to identify if it is a common lilac or a dwarf cultivar. Make the sample 10 to 12 inches long.
Q: I am working with a customer who has lilacs that look more like trees than bushes. The lilacs are at least 15 feet tall. Is it possible to top the lilacs down to his fence height or just prune the smaller growth and live with the height? Is fall the best time to cut and prune? (e-mail reference)
A: Topping will produce only ugly looking plants that won’t make you happy. Prune the lilacs in the spring, right after flowering. I would suggest doing a three-year reduction in size. Take out a third of the volume each year by cutting the large branches to the base of the plant. That will keep the plants closer to their natural shape, but with new growth generated each year and the flowering constant.
Q: I have a double problem. I cut down an old lilac bush. Underground bees now have made their home in the stump. I started working on the edge of the stump and was greeted by a small cloud of bees or wasps. I am not sure what they are. I did gradually back away, so they quieted down and went back underground. How do I get rid of these insects and can I use something that will get rid of the insects and work on rotting the stump at the same time? I would prefer something natural, but I am open to something that will not be a major problem to the environment. (e-mail reference)
A: They are probably wasps. You need to get rid of them before you do any digging again. There are wasp insecticides in pressure dispensers that are effective in eliminating them. You need to hit the nest in the evening or early morning (best) while the temperatures are cool and they are in the nest. Stand back, make sure the nozzle is pointed in the right direction and let it fly for eight to 10 seconds. If none fly out after you or you don’t see any buzzing around when you return to work on the stump, you have been successful. For the stump, get a material called, of all things, Stump Remover! A saltpeter concoction works slowly to decompose the stump. Follow directions on the container.
Q: We have 13 Miss Canada lilacs that were planted in 2004. They did bloom this summer and last, but they have shriveled up/dead tips on them instead of new growth. The stems are alive and the leaves are fine, but the tips of each stem are dead except for a few on two of the plants. They are not overwatered and get full sun. They were mulched with rock and have landscape fabric underneath. Any suggestions as to why they aren’t growing much? Thanks! (e-mail reference)
A: The rock over landscape fabric is a problem. It likely has created anaerobic conditions for the root zone. This could account for the reduced growth and possibly lead to the death of the plants.
Remove the rock and fabric, replace it with organic mulch or allow the soil to remain bare.
Q: We have some old lilac bushes on our lot line, but we are not sure of their age. In the past, they have flowered nicely. Adjacent to the bushes we have a wildflower/weed area. Last spring, my husband burned off the wild area. This spring, the lilac bushes did not bloom. My neighbor insists that we killed the bushes. The bushes still have green leaves on them, so I say they are not dead, but he is convinced we did something to harm them. Could the fire next to the bushes have damaged the soil or adversely affected these lilacs? Any ideas you might have would be greatly appreciated! (e-mail reference)
A: Any plant that produces green leaves is not dead, so that’s the end of that argument. What the fire probably did is kill the flower buds that were to bloom this year. Tell your neighbor to take a deep breath and stay calm. The lilacs probably will bloom next spring, assuming no more fires take place and no one does any pruning this year from this point on.
Q: I have planted a row of bare-rooted, old-fashioned lilacs. I want to use the lilacs as a border and a wind and snow fence, so I planted them around the edge of my yard. I have a huge yard and I am in the middle of nowhere. Where my yard is, I have a good feeling as to how the pioneers felt! (I hardly have any trees in my yard, so the winters are a bear.) The lilacs only are a foot or so tall. I have read they are a moderate growing plant and should reach 20 feet in maturity. About how many years will it take them to reach a decent height for blocking wind? How fast growing is moderate? Will they be a good size 40 years from now when I won’t be able to enjoy them? Any tips on getting them to grow fast and thick? (Kennedy, Minn.)
A: Barring any calamity, they should be their full size of 20 feet or more in much less than the 40 years you have to retirement! Moderate means anywhere from a foot to a foot and a half a year.
Q: I have two questions and I was told you where the best source for help. I have two lilac bushes that I think are Miss Kims. They flowered after they were planted, but it has been two years since they bloomed. They get enough sun. Someone told me I might have too much nitrogen in my soil. If it’s true, how do I get rid of it or is there another reason for the bushes not flowering? I have a snowball bush that is doing wonderfully. I think it is a viburnum plicatum (big white snowballs). The other day I noticed three huge suckers coming straight through the bush. The bush is young and very close to the ground. Should these suckers (if that is what they are) be clipped off or is it trying to make the bush taller and it should be left alone? When is the best time to prune and should I prune it well to encourage it to grow taller? (e-mail reference)
A: Lilacs fail to flower because of insufficient sunlight, planted too deeply, too much nitrogen, improper pruning or winterkill of the flower buds. You said the lilacs get plenty of sunlight, but unless you used a lawn fertilizer to provide nutrients, it isn’t likely too much nitrogen is the problem. If you planted too deeply, pull some of the soil back so the top of the roots are slightly exposed. If you pruned in July, then doing so removed the flower buds for the next growing season. If winter killed the flower buds, then hope for milder winters or purchase hardier lilacs.
In regards to your snowball bush, you have sucker growth coming from the rootstock. Prune it out immediately. Many viburnums are grafted on seedling rootstock that is not the same as the plant you want. Viburnums never should be shaped, so allow it to grow in its natural form. If they need pruning, do so by removing the oldest canes at the base to encourage new growth to thicken and develop the plant, but don’t do it often.
Q: I have lilac bushes that apparently are planted too close to the foundation of my house. I’ve been told to move the bushes so they don’t cause a problem when they get bigger (with the drain tile and the foundation). How do I remove the bushes? Can I replant them in another location? When is the right time to do that? I look forward to reading your column each week. I enjoy it immensely. (Fargo, N.D.)
A: I doubt the lilacs will be a problem to your drain tiles or foundation. If you still want to move them, now is not a good time. Early next spring or late this fall, after the foliage drops, would be better. Thank you for the nice comments about the column. Glad you are a faithful reader!
Q: Our lilac is about 18 years old. This spring it began to flower in May. After a heavy rainfall, it toppled over and was uprooted. Is there anything we can do to save the tree? It is lying on its side. (e-mail reference)
A: You can try resetting the lilac as best you can and see if it will survive. There is bound to be some die-out from this kind of treatment. With a lilac that old, there are bound to be some roots that will send up suckers for you and begin the process over again.
Q: I just purchased arborvitae and American evergreen trees and received 10 free French lilacs with them. My husband and I are starting a tree garden and eventually will move them after our home is built. Can we plant these together? Can you send me some information on caring for French lilacs? (e-mail reference)
A: Why not just speak “French” to the French lilacs and only use the finest fertilizer from the Bordeaux valley of France! Just kidding. I felt like being silly after a long day of answering questions! Actually, the French lilac is any number of so named cultivars of the original syringa vulgaris. They came from the Balkans, where winters can be harsh, summers dry and rocky soil the norm. Our climate mimics their origins and they have survived for a century or more throughout the country. Napoleon cultivated lilacs in his royal gardens, so they came to this country as a “French” lilac. Lilacs don’t like to be kept too wet, need full sun, little fertilizer and careful pruning. That is assuming you want to enjoy the flowers that have made them so famous. Prune right after flowering if it is desired or necessary to do so. Other than that, they just need to be admired for the beauties they are. Enjoy!
Q: I just ordered some lilacs through the mail. Do you know how long it takes lilacs to reach maturity? Will they bloom the first season? The magazine I ordered from did not mention how quickly they grow or where to plant them. I purchased three plants. Should I order more? The varieties are sensation and beauty of Moscow. I am a rose gardener at heart, so lilacs are new to me. I hope to get these plants off to the best start possible. I use Miracle-Gro on my roses and have had amazing results. I know from reading your Web site that lilacs do not need a lot of fertilizer, but I figured fertilizing the lilacs when I plant would give them a good start. (e-mail reference)
A: If you had written me before ordering them from a mail-order source, I would have advised against it. Lilacs are not that expensive to purchase locally and you get to pick the ones you want rather than just the next one that comes down the chute to be sent out. It probably will take at least two to three years before any blooms show, depending on where you live. I know nothing about the cultivars you ordered, so I don’t know if you ordered the right quantity. Miracle-Gro is the universal fertilizer for healthy, vigorous plants.
Q: I would love to install a lilac fence that is 30 feet long and 8 feet tall. Will Persian lilacs grow that tall? If I buy them at 3 feet tall now, will they ever get to 8 feet tall? The nursery has Ellen Wilmott lilacs in stock. Do they grow quickly? I live in zone 5. (e-mail reference)
A: I would go for the Ellen Willmott lilacs. It is a double-white cultivar of the common lilac that should provide a beautiful show for you. Everyone gets impatient for plants to grow. Lilacs are not slow growers, but they are not fast growers, either. Healthy plants will have decent growth every year, depending on the conditions existing at the site. Growth that is too fast is more susceptible to insect, disease and environmental problems.
Q: I planted a lilac bush about five years ago. The first year it bloomed and there were a few flowers with a lilac color. Now, every year it blooms with white flowers. The bush is beautiful. Is there anything that might be missing in the soil to produce a lilac color flower? (e-mail reference)
A: No. Something happened or you got a grafted plant where the scion wood was pruned off or that part of the plant died, so the rootstock is now producing the flowers.
Q: I want to plant old-fashioned lilac bushes to be used as a screen. How far away should they be set from an above-ground pool? I do not want them to grow under the pool or to puncture the sides. (e-mail reference)
A: I would plant the lilacs at least 15 to 20 feet away from the pool. The more distance, the better.
Q: I have a beautiful lilac that greens up beautifully every spring and has many beautiful purple blooms. They smell great! However, every year one stem of the bush seems to die. All the leaves fall off and it looks dead. The next year it comes back with green leaves and blooms. Then another one will lose its leaves. I can’t figure out what’s wrong. (e-mail reference)
A: I don’t have any idea what is causing the problem. Sorry!
Q: Is it OK to trim to the ground the new growth on my lilacs? I like the way the old growth branches out because it gives the lilacs the bonsai look that I like. (Watertown, S.D.)
A: It should not hurt because that growth is all suckers.
Q: I have a row of honeysuckle and a row of lilac trees. They are about 25 years old. They have overgrown to the point that you can’t walk through them and the branches are lying on the ground. Can they be trimmed or will they die because they are so old? (Gardner, N.D.)
A: If they were alive last year, chances are excellent that they still will be alive now, with some dead branches thrown in. Cut them back to the ground with a chain saw before they leaf out and then stand back! You will get a surge of growth that will overwhelm you, but very few, if any, flowers that year.
Q: We have a 14-year-old dogwood. It had a mixture of reddish, flexible canes and brittle brown canes. We pulled out or cut down all the brittle canes. There is green at the base. Was this the right thing to do? In addition, do established lilac bushes do well after transplanting? (e-mail reference)
A: You did the right thing with your dogwood. Lilacs transplant well as long as they are not coming into leaf; so transplant lilacs while they are dormant.
Q: My 20-year-old lilac bushes bloom profusely each spring with purple flowers, but this year all the flowers are white. Why? We pruned heavily last year, which is the only thing I did differently from past years. (e-mail reference)
A: You probably pruned past the bud graft union on the plant. What you are seeing is the flower from the rootstock. That is the only rational explanation I can come up with.
Q: My daughter would like to be married in August and wants to have lilacs in her wedding. Any ideas on where I can get lilacs in August? (e-mail reference)
A: You might try someplace where there are mountains, such as Colorado. My wife and I saw lilacs blooming in the Colorado Rockies in July at about the 8,000 feet. I have no other suggestions.
Q: I live in Seattle. Next door is a lovely lilac bush that hasn’t been cared for in the last 10 years. The house has been sold and the building will be bulldozed down, including the lovely lilac. The neighbors and I were wondering if we might be able to take a cutting. The tree has started to leaf out, though the leaves are not fully open. Any ideas you have would be greatly appreciated. I believe the bush is too large for us to dig up and transplant without considerable cost. (e-mail reference)
A: Try digging up some suckers from the roots. They would have a very good chance of surviving if you get to it right away. Cuttings do not root very well.
Q: I am looking for information on how to keep common lilacs from spreading. We are concerned about them spreading to our neighbor’s yard. Can we dig up the suckers or would mowing over them be enough to control them on the neighbor’s side? (e-mail reference)
A: There are barriers that go down 6 inches or more that should keep the lilacs from spreading to your neighbor’s yard. The barrier could be a poly-based material, steel edging or copper screening. There are many products on the market. Mowing only will exacerbate the suckering once it begins, not quell it. You can tell your neighbors to get some Sucker Stopper RTU to spray on the growing tips as they come up. This might drive them crazy and destroy a good relationship. The product also is very expensive.
Q: We moved to Minnesota last year from the East Coast and planted (around June) a row of lilacs to create a border between us and our neighbor. They seem to be doing well. Do we need to do anything special for them this winter? (e-mail reference)
A: The lilacs will be able to stand anything the Minnesota elements can throw at them. Any action you may take is more threatening to their survival. If they were not “bedded” when you planted them, do so now. You don’t want to be mowing or weed whipping between these plants. If you have grass between them, carefully kill it off with Roundup and mulch over the area just prior to the soil freezing. Keep a 2- to 3-inch mulch-free area around each plant to prevent rodent and disease problems. The mulch should be organic, such as wood chips or shredded wood, and no more than 2- to 3-inches thick. Welcome to the Midwest! The best place in America to live!
Q: My wife purchased some dwarf lilacs to plant next to our house. How close to the sewer outlet can we plant them? I hear the roots will grow through the pipe. How long do these roots get? (e-mail reference)
A: The roots will grow into sewer and water lines that leak. The roots will follow the path of least resistance where water, air and nutrients exist. Planting the lilacs 8 to10 feet away from the sewer line should be more than enough distance.
Q: I have five pruned lilac trees gracing a walkway in my front yard. One is a bushier and much larger variety than the other four. When is the best time to prune them? Also, when should I cut back flowers that are done blooming? (e-mail reference)
A: The best time to prune any flowering plant, assuming the fruit or seed is not wanted, is immediately after flowering. This would include your lilacs and peonies, as well as any other herbaceous plants. Often, timely pruning will result in re-blooming of the plants in the same season.
Q: I just looked at a row of young lilacs with leaves that are turning brown and dying. I know there was a lot of standing water near them for some time, but apparently they were not actually standing in water. I dug up some soil and found it’s still very saturated. I’m suspecting just too much water at the root zone cutting off the oxygen to the roots. I also saw swelled main stems on a few, which may possibly be borer. The lilacs are on the north side of a high fence with large cottonwoods behind the fence, which shades them most of the day. (Cando, N.D.)
A: They could have a double whammy, too much water in the root zone, which led to a borer attack. It’s not the first time this has happened and it won’t be the last!
Q: I have a customer that wants some mature lilacs and a couple of mature spireas moved. They have to be moved within a week as she is putting an addition on her house where they are now planted. I suggested that it is the wrong time of year and it might be cheaper to start over, but she is attracted to the plants. Should they be cut to the ground when moved or not until later? (e-mail reference)
A: You did the right thing in advising your client of the poor timing of this move. If she insists, do it without any guarantee on your part. Cut the plants back as you suggested and some new regrowth should take place before freeze-up. In all likelihood, they will survive with good care, but won’t flower for a year.
Q: We live in a townhouse. Our back patio is concrete with a three foot span of soil around it for gardening. One or two years ago the caretakers planted a lilac bush. They just moved out and told everyone to take whatever plants we wanted. I couldn't put in my usual vegetable garden this year, so I have nothing in my garden. I would like to dig up the bush, but can’t wait until next spring because new tenants are moving in. How far down do I have to dig? Can I separate the new shoots and put those around my fence line? Do I need to fertilize right away? (e-mail reference.)
A: Dig up as big a rootball as you can handle and plant it at the same depth. Water it in well, but do not fertilize. Do not use chemicals, especially those that are intended for weed control.
Q: It appears that I have killed my lilac bush. I am a new home owner and not experienced on how to prune shrubs and other flowering plants. I mistakenly pruned the lilac bush at the same time I was told to prune my roses. I am very sad because my bush, which was growing well until I pruned it this spring, looks dead. (e-mail reference)
A: You did not kill it, but it will not flower for this season.
Q: We bought a condo this past winter with a lovely lilac bush in the backyard. The lilac bush has now gotten so big it's taking up half our yard. How should I trim or thin it out without doing any damage? I really would like to be able to put my grill and picnic table out back. (e-mail reference)
A: Get some long-handled loppers and cut down about a third of the canes as close to the ground as possible. That should clear some space for you. Next spring, borrow someone's chain saw and cut the rest back before the plant comes into leaf. The resulting surge of growth will allow you to shape it to the size you want. You will not get any flowers next year, but that is a small price to pay to be able to grill outdoors!
Q: Have you ever heard of a miniature lilac bush? (e-mail reference)
A: Yes, there are miniature lilacs, which are becoming more popular with homeowners each year. The palibin cultivar gets 4-feet tall and 5-feet wide, Tinkerbelle gets 5-feet by 5-feet, Miss Kim, 6-feet by 6 feet, and the littleleaf lilac (S. microphylla) gets just 4-feet by 4-feet. Any good garden center in your locality should have these or others. Cut your oldest canes down to the ground every year, but don’t cut more than a third of the total canes. Remove the seed heads as soon after flowering as possible. All of this should help increase the size of your blooms.
Q: Along my workplace parking lot and building is a row of Miss Kim lilacs. In front of those are two rows of Stella de Oro daylilies. All were planted seven years ago. In the last two years, the daylilies haven’t been blooming as well as in the past. The lilacs are doing very well and have filled out beautifully. I’m thinking they could be hindering the daylilies’ growth. We have a beautiful sea of green leaves on the daylilies, so they look healthy. I don’t think any of the plants have been fertilized since being planted. Would that help or will we have to dig up and separate the daylilies? Since we are looking at approximately 100 plants just along the parking lot, I’m hoping that digging and separating isn’t the only option. (Fargo, N.D.)
A: Let's start with the easiest option, fertilizing. If you can, apply a water soluble 20-20-20 material or something similar. It will not instantly bring them into bloom, but should help if any of the big three nutrients are short. If the lilacs are crowding the daylilies, do some selective pruning on the lilacs to allow more direct sunlight to reach the lilies. Digging and separating are the last option if the first two ideas don’t work.
Q: Why would a lilac bush not produce many flowers? (LaMoure, N.D.)
A: There are numerous possibilities such as too much nitrogen, shade, immaturity and possibly, too low a temperature, but that is unlikely where you are.
Q: Can lilacs and Lombardy poplars be fertilized with Miracle-Gro if they were just planted? Can Miracid be used on newly planted Colorado blue spruce trees? (Dickinson, N.D.)
A: These products are often used in getting plants established the first year. I have used them for as long as I can remember and have never known them to hurt any plant.
Q: We moved into our house in December. This spring, to my delight, I noticed a large, healthy looking lilac bush. However, it never bloomed. I do not know what the previous owner may have done to it. If he pruned too late last year, and accidentally removed the flowers for this spring, will they ever bloom again? If I do not prune this year, will it bloom next year? (e-mail reference)
A: Yes, it will probably bloom next year if you don't prune it this summer.
Q: We were in Saint Cloud this past weekend and noticed some very deep colored lilacs. We picked some and also noted how compact the blooms were. Are you aware of the variety? (e-mail reference)
A: There are as many lilac varieties as there are Smiths in the phonebook! Visit your local nurseries and see if you can catch some in bloom to find out what they are.
Q: Can you tell me how to harvest lilac seeds? I live in Canada and we have several hundred planted in our yard. Many are transplants from a single bush that my deceased grandmother had growing in her yard. This lilac variety has double flowers that are deep purple and are just starting to bloom. (e-mail reference)
A: Allow the seeds to dry on the plant, then harvest and spread on a table covered with newsprint. Select the largest seeds and plant them no more than two inches deep.
Q: I have two older, very tall lilacs planted close together. One has many leaves and blooms while the other has a lot of blooms but the leaves are not as full. What do you suggest? (e-mail reference)
A: Some rejuvenation pruning right after they are done flowering. Cut about a third of all the older canes back as close to the ground as possible. The plant will send up a flush of leafy growth that should bud this summer and look better next year. Repeat the process every year until you have pruned all the older canes.
Q: I have a lilac bush that is growing nicely, but the blossoms never fully bloom. Someone told me that you must have a male and female plant for them to bloom. Is this true? (e-mail reference)
A: That is not true. Poor blooming could be due to a number of factors. You may be using a fertilizer with too much nitrogen in it such as the material that is used for lawns. You may have a situation where the lilac is not getting enough sun. Lilacs need full sun to bloom well. Any pruning after July 1, in general, risks the removal of the flower buds that have formed for the next growing season. The bush may be planted too deep or you may be using a cultivar that is not adapted to your particular climate.
Q: I planted a lilac shrub two years ago. This year a large piece broke off just as some buds were starting to open. Is there anything I can do to save this piece? (e-mail reference)
A: No. Treat it as a cutting and place it in a vase with tepid water and an unbuffered aspirin. It will probably flower somewhat before dying. It is living off the stored carbohydrates in the stem of the branch. Once depleted, the leaves will die.
Q: I have two lilac bushes that are relatively close to my house so I try to keep them small and under control. However, I constantly get suckers coming up from the roots. How can I get rid of these suckers without hurting the bush? (e-mail reference)
A: There is a product on the market called Sucker Stopper RTU (Ready To Use). It is not cheap, but testimonials have said that it works. I haven't researched it so you will have to believe the testimonials. Other than that, there is nothing else available as far as I know.
Q: My lilacs are in full bloom. I notice when I cut the blossoms they only last a day or two and shrivel quickly. When they are professionally cut by a florist, I've seen them last a week or more. I read that there is a special technique to cutting lilacs to prolong their bloom as a cut flower. I cannot recall what the technique was. Do you have any insight to this mystery? (e-mail reference)
A: The trick to getting lilacs to hold their bloom longer is to cut them as some are just starting to bloom and doing it in the early morning while the tissue is full of water. Remove most of the foliage from the stems. If you want leaves, include those as a separate cutting. Take eight ounces of tepid water, eight ounces of a soda drink such as 7-Up, a teaspoon of bleach and then stick the cuttings into this alchemists mix! The mix provides carbohydrates and water, and the bleach stops bacteria from forming, which clogs the stem and prevents water from being taken up.
Q: I just purchased a Pocahontas lilac. It is dark purple and very fragrant. It has four or five flower stalks on it, but we want to have more next year. Is there anything I can do to the stalks that don't have flowers to encourage them to flower next spring? Also, we have a Donald Wyman lilac which blooms later than traditional lilacs, but I see only one flower bud. I think I pruned it last fall. Did this remove the flower buds for this year? Should I prune it in the spring or just let it go until next year? (e-mail reference)
A: The lilac will set flower buds later this summer. Don't do any late summer or fall pruning, as you will remove the flower buds for the next season.
Q: I’ve had a French purple lilac for about four years. I keep it in a big pot because we are moving around a lot right now. It gets nice small green leaves on it each year, but it has never bloomed. Could it be root bound or should I not have it in a pot? (e-mail reference)
A: There are several possibilities why your lilac has not bloomed. The flower buds may have been killed during the winter (flower buds are more sensitive to freezing temperatures than vegetative buds are). The flower buds may have been pruned off. You may have the wrong soil pH; lilacs don't like acid soil. Lilacs do best in full or almost full sun, so your plant may not be getting enough sunlight. The bush may still be adjusting to living in a pot so it isn't able to fully spread roots and develop. Your plant may also be getting too much nitrogen fertilizer. Nitrogen encourages vegetative growth at the expense of reproductive growth (flowers). Ideally, lilacs should be planted outside. If you decide to keep it in a pot, remember that it will be slightly stressed and may not get enough of what it needs to thrive.
Q: We would like to build a fence between our house and the neighbor's. Their house is built on a second lot which used to be the yard for our house. There is a beautiful large lilac bush planted right in the middle of the property line where the fence needs to go. Can we dig it up and split it between the neighbors and us and then transplant it? I'm doubtful that will work because the lilac is old and large. My husband thinks we can trim through the middle of the shrub and put the fence right through the center. When would it be best to undertake either suggestion? (e-mail reference)
A: The best choice would be to trim through the center. If you trim back the lilacs to four to six inches of stem just above ground line, they should send up new suckers without any problem. To ensure the maximum amount of suckering, cut them back in late winter or early spring. For the least amount of suckering, trim them back in mid-to-late summer. You could try digging up the bush and transplanting it, but if it's big and old it would probably be incredibly difficult. Transplanting it would remove a large part of the root system. That’s a huge stress on any plant. It can be done, but it would take a lot of care and it would take several years for it to recover and adjust to its new site. If you decide to go this route, do it in early spring before the leaves come out. (JZ)
Q: My son Michael lives in West Fargo and has asked me which lilacs would grow best for him. As far as I know, he plans to put them on the east side of his house along a wooden fence that faces the street. (Minot, N.D.)
A: There are a variety of lilacs that perform well in this area. Some your son may want to try include: common lilac (Syringa vulgaris), late lilac (Syringa villosa), copper curls lilac (Syringa pekinensis SunDak, an NDSU release) or ivory silk lilac (Syringa reticulata Ivory Silk).
The city forester of West Fargo, Yvette Gehrke, may have some other suggestions. She can be reached at: firstname.lastname@example.org (JZ)
Q: I have a lilac that is four years old. It only has a few flowers even though it sits in full sun. This spring I found a dead branch. If I have borers, how will I know and what can I do about it? (e-mail reference)
A: If the trees do have borers, you'll see a tunnel entrance at the base of the tree or maybe at the base of the branch that died. There will be sawdust at the tunnel entrance. Tunnel entrances are about a quarter inch in diameter. Permethrin and lindane are two insecticides that are labeled for ash/lilac borers here in North Dakota, but the labels might be different in your state. Check with your local nursery or with your Extension agent to find out for sure. Good luck! (JZ)
Q: I have a lilac tree that I planted under my kitchen window three years ago. I have been waiting for buds to pop, but so far no luck. The reason I planted the tree was so the aroma of the lilac would come into my kitchen. Am I just not waiting long enough, or is there something I can do to help it along? (New Jersey)
A: Tree age really doesn't matter when it comes to flowering. It is actually a tree's size that determines when it flowers. These lilacs may not be big enough. Too much nitrogen fertilizer may also be affecting them. When trees have too much nitrogen in the soil, they put a lot of energy into growth rather than reproduction. Also, lilacs prefer full sun and a well drained soil with a pH close to neutral. (JZ)
Q: When we moved here there were three lilacs in the yard which were pruned to a tree shape. Last year they all flowered beautifully and I only pruned the blossoms back after they finished flowering. This spring one of them has very small leaves and very small flower heads. It is planted in the southeast part of the garden in a sun/shade area. When we moved in we put rock mulch over the entire area. Could the rocks affect the tree or could the few suckers at the bottom retard the growth? (E-mail reference)
A: My bet is the rock is having a negative impact. The rock does not condition the soil and it raises the temperature during the summer. In all likelihood, you have placed the rock over either a plastic or geotextile fiber mulch. Try removing the rocks and mulch to see if the plants perk up next spring. If that doesn't work, then it could be suffering from armillaria root rot. If that's the case, the plant is doomed.
Q: I recently cut some lilac blooms from my son-in-law’s bush. I noticed that there were seed pods on some of them. Can these seeds be planted? (E-mail reference)
A: Give the seeds cold, moist stratification for about three months. For stratification, I suggest the crisper of your refrigerator with the seed packed in damp sphagnum moss. Plant them in a sunny location and just barely cover the seed with soil. Treat the seeds like you would any other seeds you’ve planted. If they are viable, you should see some seedlings emerging in a few weeks.
Q: I have two large lilac trees in my yard that only flower on top. I would also like it to bloom in the lower areas. Any suggestions? (E-mail reference)
A: The plants will benefit from selective pruning. Remove some of the oldest canes as low to the ground as possible. This will stimulate new growth that should be productive in bearing flowers. Remember that lilacs set their flower buds for next year on this summer's growth, so don't do a lot of extensive pruning in late summer or fall. Prune right after or as the flowers fade.
Q: We have a huge lilac bush that we would like to get rid of. I think it is a Korean dwarf, although there is nothing small about it. What do you suggest? Also, what can I add to my vegetable garden to get better results? I had bad luck last year with my cucumbers and pumpkins but the tomatoes did well. I recently added some compost. (West Fargo, N.D.)
A: Cut the lilac bush down with a chain saw and treat the stump(s) with RoundUp right away. Spray any suckers that come up in the surrounding area, as if they were weeds, using a broadleaf herbicide that is selective for lawns. The garden probably needed compost. Work it into your soil and then fertilize with Miracle-Gro. You should have a decent garden this year if the weather cooperates.
Q: I heard about a particular type of lilac bush that blooms multiple times a year. Can you tell me what the name of the lilac bush is? (E-mail reference)
A: While there are lilacs that bloom at different times of the year, I have never heard of one that blooms more than once a year.
Q: I moved onto a property that has lilac bushes. The previous owner transplanted them approximately three years ago from established bushes on another property. The bushes are about two feet tall. The previous owner told me that each year the bushes get green leaves but do not flower. These bushes appear to be alive, so I want to save them. (E-mail reference - Rush City, Minn.)
A: I’m guessing they are planted too deep. Try pulling some soil away from the crown to see if that helps. You will not get results right away, but you should see some next year. If the plants do not respond to this treatment, rip them out and replace with new lilac shrubs. Life is too short to wait for a pouting lilac to decide to bloom!
Q: I have a lilac bush growing next to my house. I want to get rid of it and build a deck this spring. Is there a way to kill it permanently without having to dig it up? What is the easiest way to dig it up if that's the only answer? I understand there is quite a root system under the bush. (E-mail reference)
A: Get a shrub and brush killer herbicide and spray it on the plant. That will do it, I assure you. If you want to make sure, after the plant appears dead and you cut it out, paint the remaining stub with the herbicide. It should translocate and kill the entire root system.
Q: I have several lilac trees that are eight to ten feet tall, approximately three feet apart and approximately two feet away from a chain link fence. I would like to get rid of all the grass between the lilacs and behind them up to the fence so that I can plant perennials, put down mulch and not have to mow between the lilacs and the fence. Can I just dig out all the grass with a flat blade shovel or do I risk damaging the lilac’s roots? Is there another way to get rid of the grass and prepare the area for planting perennials? (Minneapolis, Minn.)
A: Spray the grass carefully with RoundUp. Plant your perennials directly into the dead grass and then mulch.
Q: I have a few questions about lilacs. Is a snowball tree actually part of the lilac family? I recently had to remove an old lilac from my back yard. In the process of removing it, we noticed that the bark had clean holes in it all the way to the trunk. What would cause this? I have another lilac next to it. Will it die also? Are lilacs actually trees or bushes? (Email reference)
A: Lilacs are shrubs. The holes in the trunk are caused by borers. If your remaining lilac is under stress, it may also attract borers. The snowball (do you mean viburnum, hydrangea, or ceanothus?) is not a part of the lilac family. The terms tree or shrub are usually relegated to size and whether it has multiple (shrub) or single (tree) stem. Some nurseries or homeowners train what would otherwise be a shrub into tree form or visa-versa.
Q: I have a friend that would like to have a lilac bush. I have been told that if you bend a branch with a flower on it into a large coffee can and cover it with soil, it will grow. Is that true? Is there a better way to share my lilac with a friend? (Email reference)
A: You are better off digging out a sucker from the base while it is still dormant and then transplanting it. Everything will happen much faster that way. Lilacs are not that expensive so why doesn't your friend just buy one at a local nursery?
Q: I have a President Grevy lilac that has healthy foliage, but I only get one or two blooms (if any). It is at least 15 years old and planted in full sun. I have limed the ground to sweeten it and fed it bulbtone fertilizer. What else can I do to get it to bloom? Also, last summer some bees attacked my lilac every day and fed on the bark. They would leave late afternoon and return the next day. The bees were dark brown in color. Do you have any idea what they might be and what I can do so that I don't have this problem again this year? (E-mail reference)
A: You might try some rejuvenation pruning this spring before leaf-out takes place. The bees may be "cutter bees" that cut loose bark and leaves for their nest. They generally are not a problem. If they come back this year, follow them to their nest and possibly have them exterminated by a professional if they pose a threat to anyone's health.
Q: I have two old lilac bushes that need to be removed. How do I remove them without getting a ton of shoots coming up? How large do the roots get? (E-mail reference)
A: Accept the fact that you will not be able to remove all of the roots and that you will have suckers popping up all over. Treat them as weeds by spraying with a typical broadleaf herbicide. You will probably have to spray two or three times over the summer. Depending on how old they are, the roots can get as big as a person's leg.
Q: We pruned our lilac bushes quite short last year. While the bushes have grown back, we had only one lilac branch bloom. Is there a reason why the bushes didn't bloom this year? How much should the bushes be pruned and still have blooms the next year? (E-mail reference)
A: Lilacs will not bloom the following year after a heavy pruning. Allow them to grow this fall and spring without pruning and they should flower for you next spring. When pruning is needed, it should be done as the flowers are fading and before seed can be set. Any pruning after Aug. 1 (as a generalization) will result in the reduction of flowers the following year.
Q: When is the best time to plant lilac seeds and how deep? (Lehr, N.D.)
A: Plant them now at about 2 inches deep.
Q: We bought and planted 75 lilacs a year ago. We watered them a lot until freeze-up. This spring we mulched them with wood chips and continued to water when it seemed they were dry but they really haven't grown much. The tallest is about 3 feet but most are shorter. Shouldn't they be taller by now? They look healthy with lots of green leaves. We want them to be a hedge to block the dust off our busy gravel road in front of the house. Are we expecting too much too soon? (Jamestown, N.D.)
A: Patience is hard to come by when one wants something to grow and fill in quickly. You are expecting too much too soon. The plants are getting established this year by putting energy into and developing a strong root system. The plants can then concentrate on top growth, which should begin next year. Hang in there; they will eventually fill the bill for you!
Q: I have two mature lilac bushes that don't bloom in the spring. Is there anything I can do to encourage new blooms? (E-mail reference)
A: Try cutting some of the roots with a sharp edged spade in four or five places around the plant; avoid lawn fertilizers around the root zone and don't prune. If this doesn't work then they are probably in too much shade so you would need to move them to a sunnier spot. If that doesn't work, then give up and get some new ones.
Q: Could you please tell me a safe distance to plant a lilac bush from the foundation of my house? I would like to avoid future problems with larger, older roots. (E-mail reference)
A: People worry too much about roots and foundations. Plant it about 12 feet or more from the foundation if you are really worried.
Q: I have several large, older lilac bushes. They are starting to grow out of control. Can I cut off the outside new growth or do I have to cut the bushes off at the ground? Is it better to cut the old cracked branches off at the ground to aid in new growth? (E-mail reference)
A: Get some good pruning loppers and cut the oldest canes back to the ground. Trim back no more than a third on the rest of the growth, if necessary.
Q: I planted a lilac bush last summer that grew and bloomed nicely. This summer it bloomed but then the leaves turned brown and it appears to have died. That part of the yard has been really wet this year. Could that be the problem? Is there any chance of saving it? Should I leave it and hope that it comes back next year? Should I cut it back? (Fargo, N.D.)
A: Check the cambium to see if it is still green by scraping your thumbnail along one of the stems. If it is, there's a good chance that it will come back next year. If not, then it is likely a goner. Lilacs are tough, but they don't tolerate standing water very well.
Q: I have a question about transplanting lilac bushes. Can I dig some out now and transplant them? They are only about a foot and half tall and are new plants that have come up beside the larger ones. (Jamestown, N.D.)
A: You can give it a try since there is no big investment. Plan to dig them up on a cloudy, cool day and toward evening. Get as much of the root system as you can handle then plant them in the new location immediately and water them in completely.
Q: This spring I planted a row of seven poplar trees, a row of 35 Lilacs, a row of 15 sumac and a grouping of three red maples. All of the plants came from our county Soil Conservation Service. I've made about 20-24 inch diameter rings to hold mulch out of thick plastic edging for each tree or bush. They all seem to be doing very well. I’m almost finished putting plastic and rock on top of each row to prevent any grass or weed growth in between the trees. I mulched heavily inside each ring with cypress mulch and water thoroughly once a week if we don't get rain. The trees and the landscaping all look great but are there any problems that the plastic and rock could cause? Is there anything else I should do to keep them healthy? (Lisbon, N.D.)
A: It sounds to me like you’ve given the project a lot of thought and done a lot of work to get these plants established. If you haven't overdone the mulch around the plants (greater than four inches), they should be ok. It certainly will not be your fault if they don't turn out beautifully!
Q: My wife and I noticed that there are two colored flowers on one of our lilac bushes. This is the first time we have seen this. Is this unusual for lilacs? (E-mail reference)
A: I would say it's unusual because I've never seen it before. It's probably a somatic mutation of some sort, which can only be reproduced via cuttings from that particular stem. Enjoy!
Q: You have often mentioned pruning lilacs back to ground or soil level. What does that mean? I have two lilac bushes in my back yard which seem to bloom much later than everyone else’s. They bloom but not for very long. Everyone says we should prune them back but I don’t have a green thumb. I haven’t the foggiest what pruning back means. I have always enjoyed the smell of lilacs and would love for these bushes to thrive. (E-mail reference)
A: Lilacs should be pruned back to ground level only if you want to rejuvenate the plant. Normally, to keep them to a manageable size, keep them pruned on a regular basis to suit your taste. Do it right after the flowers have faded but before July 1. I would suggest purchasing a couple of good books on gardening and horticulture from a local bookstore.
Q: I just bought a house with a huge lilac bush right by the house. I would like to get it away from the house but it has a huge trunk. Can I get little lilac bushes even if there aren’t any growing from the ground, just a big trunk? Can you grow roots from branches? (E-mail reference)
A: Yes you can. It’s called asexual propagation via cuttings. You can also be assured that if you were to cut this shrub down, you would get a plethora of sprouts coming up from the root system. That may be the easiest thing to do. You can then dig up the desired sprouts next spring before they leaf out and plant them where you wish.
Q: We have a 27-year-old Marc Michel lilac. It still blooms but only on top. Some of the main branches are dead and on many others the bark is split and drying and even dropping from the branches. Normally this variety blooms the standard mauve color but part of this tree blooms very light, almost white. There are very few leaves on many of the branches. Should we prune it severely? (E-mail reference)
A: Cut the old, dead branches out completely back to the ground. This should cause a surge of new growth which you can then fashion to your desire next year. Do this every year and you should have a perpetually young plant. If there is no response to this treatment, then it is time to replace the shrub.
Q: When is it safe to trim my lilac bush? It is growing too large and I would like to cut it down to four or five feet. (Moorhead, Minn.)
A: It would be better to cut the tallest branches as close to the ground as possible. Do it to a third of the branches each year which should keep everything in check at about the right height for you.
Q: I have a beautiful lilac shrub growing in my backyard. Since I don't spend much time in my backyard, I would like to transplant half of the shrub to my front yard. Is it possible to pull part of it at the root-ball and transplant that part or would it kill the whole shrub? (E-mail reference)
A: You can but not now unless you live inside the arctic circle. It would be better to wait until next spring, perhaps around the first of April while they are still dormant, to do the dividing.
Q: My wife and I just bought a new lilac bush and planted it against a wall of our house. Is there any danger of the roots breaking through the basement wall over time as it gets bigger? Would you suggest moving it away from the wall? (E-mail reference)
A: Only if you have a leaky, weak foundation or it is so close as to interfere with the overhang from the roof.
Q: We bought a house that had a nice landscape design but everything was badly overgrown. The Korean lilac was enormous so my husband sheared it back several times but did not go deep inside and thin it. Now it is a very dense ball with branched ends but empty inside. It is still too big for its space. I have been trying to thin it from the inside but that makes holes in the plant. Can we cut it back to remove all the leaves and new shoots for a few years or would that kill it? Is there a way to make it significantly smaller with all those bare branches inside? (E-mail reference)
A: Your question comes too late for this year so keep this answer in mind for earlier next spring. Cut it down as close as you can to the soil line before new growth begins next spring. It will send up a flush of new growth that you can then shape and thin to your heart's content. If that seems too drastic, then remove about a third of the canes, down to the base, each year for the next three years and new growth will emerge as in the first suggestion.
Q: I have been told by a friend that if you cut flowers from lilacs that you will never get a flower on that branch again. I started a purple lilac from a big bush about four years ago and this is the first year it flowered. There are clusters of two or three on three different branches. Will it hurt the bush if I cut them? Will it flower again? How far down should I prune in the fall? (E-mail reference)
A: It will not hurt the lilac to cut the flowers and shame on the person that told you that. The only way a lilac will be kept from flowering, assuming all else is equal, is to cut the plant back in late July or August. The flower buds have already formed for next year's show by that time.
Q: I planted three lilac bushes last year. I believe two are primrose and one is a sensation. I’m not sure if I am supposed to prune it before it blooms. Can you please tell me the proper thing to do for lilacs at this stage? They were very small when they were planted but now they are about four to four and one half feet tall but thin. They have never bloomed but I’m assuming that’s because of plant immaturity. What do I need to do so they are not tall and spindly and yet not hurt my chances it will blossom? (E-mail reference)
A: Prune them right after they have blossomed which should be sometime in early July.
Q: I've heard that grass will not grow under lilacs. If that’s true, can you suggest other plants that I could plant around or near my lilacs, that would thrive and survive? I have three old fashion lilac bushes and will be getting five Korean lilacs with my new landscaping project. The landscaper plans to put rock around the bushes, which is fine, but I would like to add more plants and flowers to my back yard to fill in the gaps and add a little interest. Any suggestions? (Minneapolis, Minn.)
A: My first suggestion would be to try to talk the landscaper out of using rocks as a mulch unless you are in an extremely windy location. Rocks, in my experience, are always finding their way onto the lawn. The perennials that will grow in shade include: geranium, hecuhera, hosta, primula, vinca minor (periwinkle) and Viola. Add to that some begonias and impatiens and you have a nice selection to choose from!
Q: I recently purchased a maiden’s blush lilac. The tag says it grows to be about 8-10 feet in height. I’m wondering how wide it will get because I'm trying to decide where to plant it. (E-mail reference)
A: It will get at least as wide as it does tall. Give it plenty of space. You've picked a beauty!
Q: We have recently cut down our lilac tree and are now trying to get rid of the root bowl. We favor digging it up so that we can replant quickly. However, it is very large and it already has taken several days of digging and is nowhere near half done. Also, it has been suggested that the roots could re-sprout using this method. If we had the roots treated, how long would it be before the root bowl rotted down enough for us to re-plant? If treatment is the best method, who would you recommend? (E-mail reference)
A: I would suggest hiring a tree service company that has stump remover capability. They will come in with a grinder and turn the stump into sawdust, along with any roots they can reach. Save your back (and possibly your marriage) and have a machine do the work! Sprouting from the roots that remain - you cannot get them all out - will occur if the plant was alive at the time of removal. That can be controlled with a simple broad-leafed herbicide is used to control dandelions in a lawn. The natural rotting method could take years and you would still get sprouts.
Q: My lilac bushes (probably 20 years old) not only have powdery mildew, but also have moss growing all over the lower branches. What type of product should I purchase to solve the problems? (E-mail reference)
A: Improve air circulation and light penetration for the shrub via selective pruning. The humidity is too high and direct sunlight is too low. The moss growing on the lower branches will not hurt anything but is indicative of the conditions I mentioned. Buy a product put out by Schultz called Fungicide 3 which is a neem tree extract. It does the job of controlling mildews and other fungi along with being a decent insecticide and miticide. It should be available at your local garden supply stores.
Q: We moved into a house last year that has lilacs in the front and side of the house that are about 16 feet high and very thick at the top but very sparse at the bottom with lots of dead trees in between. We want to get these under control and have them thick from the ground up and about 6 feet high. What is the best thing to do? I have been given two very different opinions, cut all the way to the ground and never cut all the way down. (E-mail reference.)
A: Include this with death and taxes as far as certainty goes: cutting old, tall lilacs right back to the ground in early spring, before new growth begins, will result in a flush of growth that you can then control to your horticultural hearts content. If the plants are dead, then of course, nothing will result. But if, as you say, they are green on top and bare in the middle, they will respond.
Cutting them at the 6-foot level will leave ugly stumps that you will not be happy with.
Q: My wife and I purchased a house in Lake City, Minn. last year and it has a lilac bush in a corner near the street. Last summer I noticed a lot of dead branches and a few blossoms. When is the best time to trim and remove the dead branches? (Lake City, Minn.)
A: Early to mid-March is best. Cut them back to soil level.
Q: Help! I have two lilac bushes that appear to be very healthy. Each spring I get lots of blooms but lose the tiny individual flowerettes very quickly. If I cut some for a bouquet, I end up with a mess under the vase and a very sad looking bunch of cut flowers. Am I doing something wrong with them? (E-mail reference)
A: No, that just happens to be the characteristic of that particular species of lilac.
Q: My lilac bush, on some leaves, has a white moldy look. How do I get it off? Is there a chance it won’t hurt the plant? (E-mail reference)
A: Don't worry about the lilac. What you are seeing is powdery mildew. It’s common on almost all lilacs at this time of year all around the country. It isn't lethal, and will be gone when the leaves drop after a few frosts.
Q: The problem I have is my 8-year-old "snowball" tree (I'm unsure of it's real name but I do know it is from the lilac family) seems dead. This spring it had a few buds on it, then it froze and nothing else happened. It had always been very healthy, and chock full of snowballs. It stands about 8 feet tall. It looks dead and the branches are brittle. My husband wants to chop it down. I say wait till next spring. Can you give me a little advice? I really hate to lose it. ( Enderlin, N.D.)
A: In 99 percent of these cases, I side with the women simply because they are right! But, in this very rare instance, I have to give the nod to your husband's objective. If it was going to "regrow" from the crown, it would have done so by now. That said, if this is going to cause disharmony in a marriage, then I would suggest that it stay for another year (what harm would come from doing so?), then remove it if it doesn't live up to expectations.
Q: I have noticed some shrubs in commercial areas in the Twin Cities area that look like miniature lilac bushes. The blossoms seem to be the same and the fragrance is heavenly but they grow low to the ground . Could this possibly be a small breed of lilac? I would love to know just what they are. I have a lilac hedge (full size) and they are tall and spindly, producing only a few blossoms each year. I would like to know when and how to trim these back to about 5 feet high in hopes they would start to bush out. Maximum height now is about 7 - 8 feet. (Minneapolis, Minn.)
A: Yes, there are miniature lilacs, and they are becoming more popular with homeowners each year. The 'Palibin' cultivar gets 4 feet tall and 5 feet wide, 'Tinkerbelle' gets 5 feet x 5 feet, 'Miss Kim' 6 x 6 feet, and the Littleleaf Lilac (S. microphylla) gets just 4 feet x 4 feet. Cut your oldest canes down to ground level every year, no more than a third of the total canes, and remove the seed heads as soon after flowering as possible. All of this should help increase the size of your blooms.
Q: I am still confused on just how severe a trimming you can give lilacs. I have a small hedge consisting of eight lilac shrubs. They are placed approximately 6 feet apart. I wanted them to fill in as a solid row. After 25 years, they are shabby and are not filling in the spaces. They are approx. 6 feet high and are planted in well drained soil with sunshine all day. I want to trim then back to maybe 2 feet high to see if they will balloon out. Is that too severe a trimming? They have just finished blossoming. (E-mail reference)
A: Do that and you will have an ugly looking hedge, with everything starting at 2 feet. Basically, to thicken up your hedge leave them alone for now, and then cut them back to as close to the ground as possible next spring before leaf out. You will not get any blossoms that summer, but you should get a flush of thick, lush growth that will make a nice dense hedge. In future years simply thin out the thickest canes right back to as low as you can cut them and you should continue to have an attractive hedge.
Q: I have lilacs that are over 70 years old and perhaps older. My brother thinks they may be closer to 100 years old. Is it a lilac tree or a lilac bush? Are there both trees and bushes or are lilacs all trees or all bushes? (E-mail reference)
A: When is a plant a tree and when is it a bush? The eternal question. As in many things where beauty and definition have different meanings, it is sometimes difficult to say. But here is how I bail myself out: If it is a multiple stemmed plant and is under 15 feet tall, then it is a bush. Anything larger starts getting into a small tree category. By the same token, if the same plant is not allowed to go into a multi-stemmed growth, it could be said to be a "tree form." Either way, lilacs are considered shrubs (bushes) rather than trees, although there is the Japanese tree lilac - Syringa reticulata - that gets 20 feet or more tall and is considered by many "experts" to be a small tree, although some hedge and call it a large shrub or small tree! Take your pick! What you call it makes little difference to the plants.
Q: My husband wants to transplant a lilac bush from one piece of property to another. The bush was started about seven years ago from a twig that was transplanted. Now the bush is about 3-1/2 to 4 feet tall and is blooming for the first time this year. When is the best time to transplant this bush, with the least amount of trauma to the bush? (Beach, N.D.)
A: Next spring before the plants leaf out.
Q: I bought a lilac bush last year that is an all summer bloomer. It died over the winter and we want to replace it and can’t remember the name. We can't seem to find one that blooms all summer like that one did. Can you help with the name? (E-mail reference)
A: The 'Miss Kim', 'Tinkerbell', and the Dwarf Korean lilacs are the only ones that I know of that may have a repeat bloom during the summer. None flower continuously all summer.
Q: I have a number of lilac bushes on my property that are growing out of control. I trim them back every year, but they seem to grow back like wild fire. Do you have any advice on how to remove lilac bushes and how to keep them from coming back? (E-mail reference)
A: Treat them like weeds and spray with a systemic herbicide (like Trimec) as they resprout. It may take several applications but you will eventually win the war, and it is a lot easier than trying to dig out each and every sprout that comes up.
Q: I am still trying to find a source for purchasing a Copper Curls Pekin lilac. I called Bailey's and they are strictly wholesale. They said Bachman's carries their stock so I tried a local Bachman's. The lady there said she would need to know the botanical name to help her figure out what is what. I didn't know the Botanical name. Do you have information like that? (E-mail reference)
A: This is an NDSU introduction developed by our woody plant researcher, Dale Herman, and is known as Syringa pekinensis 'Sun Dak', aka Copper Curls Lilac. You may be a little ahead of the curve on the availability of this plant, as it has just been released to the trade and was expected to be available retail by 2003. If anybody would have it, Backman's would, or they could tell you when it would be available.
Q: I want to plant a lilac tree and flowering crab this year but need some advice about lilacs. Would it be best to plant hybrids or the old fashioned lilac? Would I need two for cross pollination? What kind of flowering crab would you suggest? I live 40 miles south of Fargo and in zone 3. (Rothsay, Minn.)
A: First the lilacs: It all depends on what you want, Fragrance? If so then the common ones are best. If fragrance isn't important, but vivid colors and mature size are, then go for the hybrids. You can have one lilac or 100; either way they will flower beautifully. Next, the crabapples. Do you want them for just the flowers with no or minimum hassle with the fruit, or is the fruit size, color, and durability important to you? There is only one completely fruitless crabapple, and that is 'Spring Snow', which is loaded with white flowers in spring, and no fruit. Then there is the 'Red Jewel', which is a beautiful, red-fruited, white flowering crab. The fruit shrivels and darkens with fall frosts, and remains on until spring, serving as a source of food for wildlife. Then there is the 'Thunderchild' crab which has delicate pink flowers and deep purple leaves. Again, one is all that is needed for fruiting, as there are usually plenty of other crabapple or edible apple species within a half mile or so for pollination and fruit set.
Q: I planted two Japanese tree lilacs near my patio. The first year they were full of blooms, the second year nothing, although the foliage was very beautiful and appeared very healthy. How can I get the blooms back? When is the best time to prune in my Illinois garden and still encourage growth? Also, how tall can I expect them to grow? I was hoping they would give my patio a little shade. (E-mail reference)
A: You probably pruned the plants too late in the season. If any pruning is needed, do so right after they have finished blooming. I assure you they will provide shade for your patio, as they will get to 20 feet or taller.
Q: Leaves on my lilac are curling up as if they are not getting enough moisture . We had quite a dry spell so I watered it regularly. It is getting plenty of moisture now but the leaves are still curling . It is 5 years old and has bloomed beautifully last year . Should I cut it back to the ground so that it can start over ? Do you think maybe it is dying? (Sioux Falls, S.D.)
A: From the information you have given me, I would try to save it by cutting it back. If it survives, it will not bloom next year, but will the following year, under normal conditions.
There are a lot of things that could be affecting the lilac; borers, canker and root rot to name a few. They are generally tough plants and come through just about any adversity.
Q: I have a lilac bush that is 8 years old. I have recently moved and would like to move it to my new house. What would be the best time to do it and should I prune it down before I try? (E-mail reference)
A: An 8 year-old lilac bush is going to have quite an extensive root system, so I hope you have a strong back! Wait until it goes dormant this fall, then cut it back as far as possible. To dig it out, I would suggest splitting the rootball, and moving the plant in two parts, planting the parts in different locations at the new location. Water in well. Next spring there should be a flush of vigorous growth that will be your new lilac. It will not flower that year but should in subsequent years.
Q: I have been recently faced with a huge construction effort on my property to repair some foundation problems. My problem is that this effort may require the destruction, removal or transplanting of two lilac bushes which are currently growing along this space. I am worried that if I do not move them they may be damaged during construction, but I am more worried that undertaking a transplant now may kill them as well. Any suggestions would be appreciated. (E-mail reference, Toronto, Ont., Canada)
A: Lilacs are pretty tough. Rather than transplanting, I suggest getting some old sheets or rags and tying the branches together as much as possible and covering with a tarp of some kind during the construction phases. If you have to cut them back somewhat to accomplish this, not a big deal. You’d just lose some blooms next year. You are right, digging them out now would not be a good idea. If the construction gets delayed until the shrubs defoliate in preparation for the winter, then you could safely transplant them.
Q: Is there a branch and leaf gall that bothers Miss Kim lilac? The leaves are curling in from side to side and I find a strange tan colored protrusion on the stem and sometimes on the backs of leaves. Is it normal for lilac to have a bumpy protrusion on the stem or are these some type of gall? (Cando, N.D.)
A: It could be scale insects getting started. Can you send me a sample?
Q: I live in northeastern Kentucky. We planted two nice lilac bushes late in May. Over the past few weeks most of the leaves have been developing dark spots which eventually lead to a dark, dry, curled-up leaf. I assume this is a fungal infection. (E-mail reference, Kentucky)
A: Most likely it is. Not much to do now, this late in the season, except to prune out the affected branches (if they are limited in number). Clean up all leaf residue this fall. Next spring spray with lime-sulfur while still dormant, and watch carefully for disease development, taking fungicide action (mancozeb, chlorothalonil, wettable sulfur, etc.) when something looks like it is starting to happen.
Q: This summer we planted a row of bare root villosa lilacs that started to bloom almost immediately. The plants are 3 to 4 feet tall. They looked great until this past week when the tips of many of the leaves started to turn brown. We watered the plants extensively in the beginning, and lately we have had a lot of rain and it has been very humid. We have heard that high humidity can cause mildew on lilacs, but there is no mildew that we can see on the leaves. What can we do to keep them healthy? (Lake Mille Lacs, MN)
A: At this writing, you are a little early to be worrying about powdery mildew, which is not toxic to the plants anyway. I am more concerned with your leaf tips turning brown. The description sounds exactly like the common pathogen Phytophthora cactorum, aka lilac shoot blight. It is the result of a spring that has been too wet and the soil not being able to handle the excess water.
Q: We moved into a house with beautiful lilacs all the way around the yard. On one side they are nicely kept and trimmed into a beautiful hedge. On the other side they are about 10 feet tall or taller and there is no fence, only the lilacs. We want to put a fence in but have to cut down the lilacs. How short can we cut them and still have them come back after we have our fence in? I don't want to kill them , but I have small children and we must have a fence so they are safe to play in the back yard. (Ames, Iowa)
A: Lilacs are pretty tough customers and can survive just about anything short of a land mine explosion. If you have to install the fence this summer, wait as long as possible to cut the lilacs right back to the soil line. This is to allow as much time as possible for the plants to build a carbohydrate reserve for next season's growth spurt. If this is something that you are planning on doing this fall or next year, then cut them back when they have gone dormant. The resulting growth next year will not produce flowers, but it will the following year.
Q: We have a 30-year old lilac bush that stopped blooming about three years ago. What do you suggest...a drastic pruning, replacement or continued patience and more TLC? ( Brossard, Quebec, Canada)
A: Replacing a 30-year old lilac bush is no small chore. It will have a root and crown system as vast as the Mall of America! If it were me, I would try chain-sawing the thing down to see what happens first. That may bring it back into a blooming cycle.
Q: A friend offered to dig up some nice lilac suckers for me to transplant in my yard. When is the best time of year to do this? Should we wait until after the bush is finished flowering, do it now while it's in full flower, or wait till next spring before it's flowered? (E-mail reference)
A: Waiting until this fall when it has dropped leaves, or next spring before it leafs out, are the better options for success.
Q: I know that you have to wait until lilac is done blooming to prune, but is there a time after that when it should be done? In other words, do you want to prune before some late date to protect next year’s buds and flowers? (Cando, N.D.)
A: The sooner after flowering lilacs are pruned the better. If pruned just as they are finished flowering, then energy will not be wasted making seed, and can go instead into new growth and making next year's flower buds.
Q: My lilac bushes aren't flowering. I have about five of them about 4feet tall, and about the middle of last summer, I pruned. Did I cause the "non-flowering" by pruning too late in the season? Will they never flower again if I pruned off the buds? I don’t remember seeing any buds. I've lived here for three years now and don’t ever remember seeing the bushes flower. Any thoughts? (E-mail reference, Massachusetts)
A: Never-flowering-lilacs could be a problem. Typically, lilacs set their flower buds in late July or early August for the following spring's bloom. If they have never flowered it could be they are in too much shade or getting too much nitrogen fertilization for flower bud setting. Try to root prune them with a sharp-edged spade in a couple of places. Such trauma will often initiate the setting of flower buds for show the following year.
Q: Can you tell me why my 5-year-old lilacs don’t bloom? ( Forman, N.D.)
A: Either too much shade or too much nitrogen fertilizer. If neither fit the bill, then you likely have selected a cultivar whose flower buds are not hardy in our climatic zone. If none of this fits, then I have no idea!
Q: One of our lilac bushes started blossoming, and then within a couple of days one half of it started wilting and that half of the bush has white spots on the trunk. What is wrong with it? (E-mail reference)
A: Sounds like borer activity to me. Cut out the affected parts and burn or otherwise dispose of them. Spray with permethrin or lindane, and try to keep the shrub as stress-free as possible with ample water and fertilizer.
Q: About seven years ago I planted a lilac bush (unknown type) on the northern coast of Maine. It is nice and green but has never bloomed. It is in a sunny, well-drained area. I have never pruned it--I'm afraid I'll kill it. Should I? How? I have never fertilized it. Should I? With what? Any help will be greatly appreciated. (E-mail reference, M.E.)
A: A lilac that has never bloomed in seven years is very unusual. You are probably too good to it, or it is growing in too much shade. If it isn't in shade, I suggest some "traumatic stimulation" to get it to set flower buds for next spring. Take a straight-edge shovel and drive it into the soil about 5 feet from the plant in about six different places. This will reduce the root system's ability to uptake water and nutrients somewhat, but not adversely affect the plant, just stimulate it into the reproductive cycle. If you fertilizer your lawn every year, give the plant a wide berth to keep it from getting the high nitrogen fertilizer that goes onto turfgrass. If you have it in shade, either remove the shade by selective pruning of the offending tree, or move the plant (this fall when dormant) to a full sun location.
Q: I am having a basement put under my house, and I have a lilac bush that I will have to move. What would be the best way to do this? I will be putting it back but it will take about a month to do the basement. Also, what can you do when you cut the flowers and put them in a vase to make them last more than a day? (E-mail reference)
A: Don't bet on your lilac surviving a move at this time of year, just as it is starting to leaf out and bloom. Depending on the size, if you can dig a big enough root ball so as to not disturb the roots, then it may survive. Otherwise, forget it and replant. There are commercial preparations that you can use to extend the life of flowers in a vase; otherwise, lime or lemon juice, unbuffered aspirin, clear vinegar or anything else that mildly acidifies will help. You need to still change the water every day.
Q: I have a beautiful lilac bush I want to get a start from and add more lilacs around my 5 acre yard. What do I take from the plant to make a start? Can I mix lavender and white lilacs? How long does it take a start to root? I have a green thumb in the garden with seeds, but this is a challenge for me. (E-mail reference)
A: Lilacs can be started by digging suckers early in the spring before leaf out, or after the leaves have matured. They do not root well from cuttings, so I do not suggest that. They are usually very accommodating about sending up sucker growth, so you should have lots of material to select from. Color mixing makes no difference, so go according to your interest and taste.
Q: I have a problem with borers in my lilacs. I plant a lilac every year, but every year I lose one to borers. What can I use for preventative measures so I don't lose any more? The borers are always at the base. (E-mail reference)
A: Spray the base of your lilacs with either Dursban (chlorpyrifos), Lindane, or permethrin (Astro), beginning in mid-May at three week intervals, three times. Try to grow your lilacs in such a way that they are not stressed.
Q: I don't know a thing about lilacs, but my friend cut down a lilac bush and I took some of her cuttings. She told me to put them in a bucket of water and they should sprout. I have done that and now they are starting to bud. I asked my friend what I should do, but she doesn't know about the lilac bush she has. (E-mail reference)
A: You have taken, I assume, what are known as hardwood cuttings, which in general do not root well. The most easily rooted cuttings are the softwood type (new growth), which exist just before the end leaves mature. If your friend has any suckers sprouting from the cut back shrub, I'd suggest digging those out carefully and transplanting them where you want the shrub to develop. Water in well, using a water-soluble fertilizer.
Q: We moved to North Carolina on the coast and I have been told I will not be able to grow lilac here. Do you know of any reason why they would not do well here? (E-mail reference, N.C.)
A: Sure. It is called high humidity, which would lead to mildew, both the powdery and downy kind that would devastate any lilac plant. You can, however, grow something that is equally as beautiful, and that is the Crape myrtle - Lagerstroemia indica. It has lilac-like blooms and interesting exfoliating bark. I really loved those plants when I lived in the south. There are dozens of cultivars that you can select from. Plant these, and you'll never miss the lilacs.
Q: I'm worried. I have many different types of lilac bushes, common lilacs to specialty lilacs. Some are almost 10 feet high. I just read a question from another reader regarding Miss Canada and when to prune her. I removed Miss Canada's spent flowers in early summer as I always have with my other lilacs. Miss Canada is a new one for me. Did I remove her new buds for this season? Should I have just left her alone? Will she flower? She is my most beautiful lilac bush. She grows so gracefully. (E-mail reference)
A: The 'Miss Canada' lilac is a cultivar of the late lilac ( Syringa villosa), which produces flowers on the current season's flush of growth, rather on last year's like the common lilac. So, in a nutshell, you have nothing to be worried about. If my answer to a former reader left you confused, I apologize. Your 'Miss Canada' should bloom beautifully this spring for you. Enjoy!
Q: My lilacs started to bud out last November when it was so nice. Now I am worried that they will not survive. Should I be concerned? (Bismarck, N.D.)
A. Lilacs are pretty tough characters. While there may be some damage from last fall's budding, I have every confidence that the damage will only be cosmetic for this year, if at all. Mother Nature, in her wisdom of plant design, very cleverly allowed for such irrational contingencies in weather patterns. Any apparent damage will be masked by flushes of new growth that will take place later in the spring or early summer.
Q: I have a couple of lilac bushes, and when spring comes
around I only get a few lilac flowers on bushes. How can I get
flower on the bushes? (Minot, N.D.)
A: Lack of flowering of lilacs is usually due to late or early season pruning. If you prune, do so immediately after flowering, as the flower buds on lilacs develop on subsequent new growth. Pruning in August, for example, would remove those newly formed flower buds; pruning in March would also remove them just prior to flowering.
If you don't prune, then the problem could be the location. Lilacs thrive in full sun, and do poorly -- flower-wise -- in shade. Another problem could be borer damage, but there would be evidence of twig death if that was the case.
Q: I have read that to create a thick (multiple branched) hedge you should cut back the top third of new hedge plantings by one-third for the first three years. I have a one-year-old villosa lilac hedge. Does the one-third off for three years work for villosa lilacs? (e-mail)
A: You bet it does! Try to get it done before July 4 so it will have time to set new flower buds for next year.
Q: Two years ago I cut down all the lilac bushes in the cemetery after the severe winter with all the snow. They had become so entangled that they were hard to clean. Now they have grown back to about 4 feet high and had beautiful blossoms this year. Here is the problem. The cemetery board wants me to cut them back to about 3 feet high now that they are done blossoming and square them off. Is this a good idea? (Selby, N.D.)
A: Not a problem to cut them back to a squared-off form. Doing it now will assure blooms next year.
I concede that the "boxed" lilacs will not look natural, but the board is obviously attempting to get the cemetery into a formal look.
The lilac flowers will still look and smell beautiful!
Q: I want to spray my lilacs and phlox to prevent mildew this summer. My phlox, next to the building, are coming up. Is now the right time to spray them, or should I wait until later? Or is it too late already? (Fargo, N.D., e-mail)
A: You are a little early to be spraying fungicide for powdery mildew control. I suggest waiting until around Memorial Day weekend or about the June 1. Or, as a little more accurate gauge, when they start flowering.
Q: Can you tell me what kind of fungus is growing on the enclosed sample of white lilac bush? I would also like to plant a new lilac there and I am wondering if it will have the same problems? (Cando, N.D.)
A: The new lilac will likely grow in the same location. Just make sure as much of the present shrub as possible is removed.
You have two maladies with the present lilac. One is the shelf-like structure on the wounded branch. What is happening is internal rot and what you are seeing are the results of this process. It is often found on old trees that have fallen or will soon fall, from internal decay.
The other disease is powdery mildew. This usually arrives on lilac leaves in late July or August. To keep under control, spray with sulfur, Bordeaux mixture or Benlate prior to the disease showing up.
Q: Could you tell me what cut flowers I could plant that would still be blooming in September. I would also like to know the best way to keep them in a vase to use as a centerpiece? Would Poast be OK to spray between my shrubs, plants or trees to remove grass? The deer broke off some of the branches on my Japanese lilac and I am wondering if it will come back or if I should get rid of it. I also am wondering if I can cut back my potentilla. My last question is if it is better to plant onion sets or onion plants. (Winner, S.D.)
A: Just about all the asters and mums would be at their peak in September. The eustomia or lizanthus makes a beautiful cut flower, as do snapdragons, zinnias, marigolds and a daisy known as Osteospermum Passion Mix.
Poast should not cause any problems as long as you follow label instructions.
Let the lilac go. It will likely come back—they're pretty tough. If you don't see any growth in 30 days, get rid of it and replant.
Pruning the potentilla selectively will not keep it from flowering; cutting it back completely at this time will—all you'll get is lush, green growth.
A horse apiece on the onions! Try both and see what results please you the most.
Q: What is keeping my lilac bush from growing and blossoming? About five years ago, I planted a lilac bush, it was about 2 feet tall but not many branches on it. Today it is filled out and greens up nicely, is about 3 feet tall, but does not blossom. I also have a peony planted in the same area that isn't blooming. They are planted by a low-lying city-owned lot where there is usually water standing all summer. Could this be the problem? (Fargo, N.D., e-mail)
A: The lilac needs full sunlight and relatively dry soil, as does the peony. Take that away from them, and no flowers! Move them if you can first thing next spring to a sunnier, drier location.
Q: What causes the whitish spots on my lilac bushes and my phlox? (Fargo, N.D., e-mail)
A: The white cast, or spots, on your lilacs and phlox are from a topical fungus known as powdery mildew. This is generally not a serious enough problem to be concerned with. These two species are especially prone to this fungus, which shows up in late summer or early fall, when the humidity is especially high, along with the temperatures.
Simply clean up the leaves, and if you wish, spray the foliage next season with a fungicide to inhibit the development of the mildew.
Q: Enclosed is a sample of grass from my lawn that is a darker green than the rest, and it seems to be taking over the other grass. I would like to get rid of it, but I'm not sure how. Also, I have an old stump from a lilac bush I sawed off to the ground to try and prevent suckers, but it hasn't worked. There are also suckers on my maple tree. What can I do to get rid of these? (Hillsboro, N.D.)
A: The samples you sent were definitely not crabgrass or quackgrass, but annual ryegrass. This, and crabgrass, are not worth controlling at this time of year. Next spring, around the time lilacs flower in your area, apply a premergent herbicide listed for crabgrass control from the enclosed circular on lawn weed control—for example, Pendimethalin ("Weed control in North Dakota Lawns"—H1009).
And, speaking of sprouts from a lilac stump, try "painting" the leaves and cut stumps with Roundup. It will likely take a couple of years, but if you persist you'll win—I promise!
Do not do the same thing with your maple tree. The only option you have at this point is to cut the suckers back!
Q: My 3-year-old lilacs are blooming poorly. I am now cutting the seed pods off. Is that the right thing to do? (Onida, S.D.)
A: The sample you sent in was of late lilacsSyringa villosaor one of its hybrids ("Miss Canada" etc.) This species differs from other lilacs in that it produces flowers on the current season's growth rather than from wood produced the previous season. You are correct in removing the seed heads. Keep it up!
Q: Would you please tell me what is wrong with my maple tree? Do fern leaf peonies take the same care as regular peonies? Are Japanese tree lilacs slow growers, and are they OK to plant in this area? Also, do you need to have two mock oranges to get them to flower? (Winner, S.D.)
A: Your maple looks as if it is suffering from too much salt (fertilizer burn or naturally high soil salt content) or is planted too deep. Try to improve the drainage around the plant site if possible, even if it means resetting your tree.
Basically, the peonies all require the same care. Japanese tree lilacs are among the most trouble-free plants to use in our prairie landscapes. They are not slow growers and have an attractive cherry-like bark. Get one!
No, you do not need two mock orange shrubs. Lack of flowering could be due to not enough direct sun, too much nitrogen fertilization or improper pruning. It could be, too, that you really don't have a mock orange!
Q. We have lilac bushes in front of our house, which we cut down as they weren't blooming very much. How can we get the main bush to grow and not the suckers or side shoots to come up? What can we do and use to kill the side shoots? Or isn't it possible to control them?
Thank you for any help you can give us. We read your plant and garden tips every Friday and have learned a lot. (Clifford, N.D.)
A. Suckering of lilacs is a typical problem with homeowners, though a desired quality in shelterbelt plantings.
You can try weed barrier cloth covered with 3 to 4 inches of mulch. Unfortunately, there is nothing that will selectively kill off the suckers. Sorry!
Q. I've not written to you before, but I turn to your column before any other on Fridays when the Farmers' Forum arrives. May I ask a few questions, please?
(1) Do small evergreens like lots of water? I bought two small (about 1 foot high) bushes earlier this summer. I delayed transplanting the bushes, but they seemed to thrive and then suddenly both died. Someone told me I need to use Miracid on evergreens, but perhaps I bought the product too late. I did water the bushes a lot.
(2) I wonder why my 15- to 18-year old Bridal Wreath died back to the ground. It is a foundation planting and was huge and gorgeous until three years ago, when branches began to die. All branches are now dead, but new growth is coming from the ground. Should I use Miracid?
(3) My beautiful 12-year-old white old-fashioned lilac bush (about 9 feet tall) is dying. Several large branches have leaves that are totally withered and brown. I began to notice the withering about Aug. 1. Might I have overwatered?
(4) My dogwood bush looks rather sick, too. The leaves have strange spots on them.
(5) I have an old (about 25 years) phlox that flourished and produced beautiful rose-colored flowers until about four years ago. Now, it begins with green sprouts (in the spring) but fairly quickly the stacks become brown and shriveled. It does not get much sun.
I would appreciate any suggestions you might make. I'm hopeful you will continue your column. (Fargo, N.D.)
A. Oh, brother! Your questions could launch a thesis! I'll do my best to provide you with direct, accurate answers based on what you have told me.
1.Evergreens do not do well under continuously wet conditions. They are generally upland plants, able to survive extended waterless periods. You most likely killed them with too much kindness.
2, 3, & 4. Spireas should be pruned each spring to remove the oldest woody canes; lilacs are hosts to borers and scale insects, and at least a half dozen fungal diseases, any of which could be causing the symptoms you describe. Ditto for the dogwood.
5. A phlox plant that is 25 years old? That has to be a world record! Dig and divide, reset in sunny locations. I am surprised powdery mildew and spider mites didn't take their toll.
Fertilizing with Miracid or Miracle-Gro certainly won't hurt anything. While it will help plants along, it won't resurrect the dead ones.
Thanks for writing and for the nice comments.
Q. I never miss reading your column in the Sun Country. It is very helpful. I want to plant old-fashioned lilacs, either a sugar maple or Norway maple, and an American linden, all purchased from Gurney's. Can I still plant them this fall, and do you have any hints that will help them survive our winters? Thank you. (Sykeston, N.D.)
A. Gurney's is a regional mail-order supplier, and their stock is usually quite successful at getting established in our area.
First, I suggest you stay away from those two maples and go with the linden. The biggest mistake people make is planting too deeply. When the stock comes in, note the soil line on the trunk and plant to that depth, water in well, but do not fertilize for the first year.
Healthy stock should take off next year.
Q. What do you recommend for lilacs to avoid mildew? The disease seems to affect the plants which have been trimmed.
I have been letting the vines crawl along the ground next to the house for the past 5 years. Last year the leaves turned brown and curly. What can be done to avoid this unsightly problem?
Thank you for your article. (Esmond, N.D.)
A. The mildew you see on the lilacs during late summer is not lethal to the plant. The likely reason it goes after the trimmed bushes is because of the more current, tender growth. It is not worth the expense of fungicide applications for control.
I am sorry, but I don't know what vine you are making reference to. I would need to see a sample to attempt a solution to the problem.
Q: I've been in this house less than two years and have a lot
of lilacs. I plan to increase my collection by purchasing
different varieties as well as planting more of the
suckers (which seem to do quite well) to surround the property for a lilac-enclosed paradise. I'd like to know exactly where one should cut the bush to prune for
maximum bloom while retaining as much height as possible and making the bushes plump out next spring. (e-mail)
A: Take some long-handled loppers and reach into the base of the lilacs as low as possible and cut back about one-third of all the oldest canes. This
would leave about two-thirds left for the bloom show and cause the plant to "plump out" as you put it (nice term, I like it!) next season. Do that each
spring and you will have perpetually beautifully lilacs to enjoy.
Q: I recently trimmed my lilac bush and kept several branches
that had little nubs. I have them in a jar with water, and
they're almost in full leaf, with some of the tips
having tiny little green lilacs opening up. I would like to transplant them to a different part of our yard. Will they sprout roots in the water, and if so, how long should
the roots be? Also, when should I plant them? The original bush is in full sun, but do my transplants have to be? (Bordulac, N.D.)
A: Lilacs can be rooted in a sand/peat or vermiculite medium, if careful attention is paid to timing. When the new, green shoots reach a length of 4 to 6
inches, cut them off and trim into cuttings. Being very succulent at this state, it will be difficult to prevent wilting.
From a homeowner's perspective, it would be best to have some distilled water handy in a mister, and as soon as the cuttings are harvested, mist
completely, and cover with dampened paper towels until they can be stuck in the rooting medium. Mist regularly, and they should root in about six
weeks. Lilacs must be planted in full sun or the flowering will be greatly reduced.
Q: I am an organic producer in Divide County and would like to plant a large number of lilacs for erosion control. I am interested in starting or propagating the lilacs myself. Do you have any information on how to start lilacs from seed or the best way to propagate lilacs? If they can be started from seed, when is the best time to collect the seed? Can the seed be planted the year it is collected or does it need to go through a dormancy period? Can the seed be planted directly into the field or does it need to be started in containers and transplanted? Can lilacs be propagated by cuttings or by digging up suckers from established plants? If so when is the best time to do so? (Crosby, N.D., e-mail)
A: Lilacs can be produced from seed being planted in the fall to go through cold stratification. Germination is generally good. They can also be dug as root suckers anytime now and transplanted to the new site with some degree of success. It is past the best time for successful taking of lilac cuttings.
Q: I had a lilac that was 10 years old, and last fall the leaves started dying. This spring it was dead and the branches were cracked all the way to the ground. I didn’t think it was possible to kill a lilac, but I have. What do you think was the problem? Also, the leaves on my crab apple started yellowing and rusting and then fell off. I sprayed it with sulfur but that hasn’t helped. Is it worth saving? Could I plant another crab a few feet from this one if it was removed? (Kerkhoven, Minn.)
A: I admit that I have not heard of too many lilacs getting wiped out. Downy mildew perhaps? Borers? A combination? I don’t know. But do get rid of the present crab apple and plant another resistant one to scab.
Q: I was so excited to discover your website while searching for information on lilac bushes. I hope you can help me. I recently moved from New York City to Maine. My new husband has six lilac bushes in his yard. I don't know the first thing about how to take care of them. Last year we had someone prune them, but this year we did not. I noticed that they are developing pods or seeds of some sort. Is this okay? Do I need to cut them off? It appears that I have more than one variety. Someone told me that one was a Japanese lilac -- bushier and the flowers are smaller than the standard type I am used to seeing. The balance of bushes I have are more of the standard type. What other care must these plants receive? Do they require fertilization? (E-mail reference, Maine)
A: You have one of the hardiest species of woody plants that can be grown in a landscape. The seed pods you are seeing are not going to hurt anything - just look a little unsightly for now. Next year, if they need pruning, do so RIGHT AFTER they finish flowering. If you prune too late in the season, you will be removing the flower buds for next season. Generally they do not need fertilization. The biggest problem with them is that they may develop powdery mildew on the foliage as the summer wears on. But this is nothing to worry about. It doesn't cause any harm to the plants, since they will usually be dropping their leaves in 45 to 60 days after appearance of the fungus, prior to going into winter.
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