Questions on: Evergreen
Ron Smith, Horticulturist, NDSU Extension Service
Q: I am enclosing some photos as well as branch samples from the evergreens in our yard. Last fall I noticed some needle discoloration, so I called on the Extension agent here. He felt the problem was a fungus and said I could wait until spring to spray or do it in the fall. I sprayed them last fall with a fungicide. He also said I could trim back the diseased parts, but thought it best to see what happens by spring. The agent checked for excessive water problems and felt that was not the problem. We have our own well with brown water and an underground irrigation system. Watering had been set for 4 a.m. twice a week. This gave the trees an inch of water a week. Now the trees look as though they are drying. The only green that is left is quite close to the center. There are shoots on them from fall that still have not begun to open, but the branches are pliable and not dried to the point where they easily break off. I have a feeling that the trees are suffering from spray drift because we are close to a road that was sprayed for weeds late last summer. Please tell me what can be done to save these trees. Thank you for your help. (Mott, N.D.)
A: The buds on the sample were dead and the foliage appeared to have salt burn symptoms. Based on this and the other information you provided, it appears the trees are in an irreversible decline from herbicide spray drift and salt spray from winter deicing activities. I suggest removing the trees. If you replant, move the planting site further into your property, so the trees are away from weed and salt spray drift. After the replanting, I suggest a protective spray with an antidesiccant. While this slows growth a little, it provides protection from aerial drifting of some herbicides and salt spray.
Q: Three years ago we had our evergreen hedges trimmed. These professionals recommended that we cut 2 feet of branches off the bottom of the trees to make them grow thicker, which I did. I am devastated that the bottom of our hedge is now dead. We can see through to our neighbor's yard on all three sides of our garden. What can I do? The hedge is the biggest asset on our property. (Ontario)
A: Obviously the professionals did not know what they were doing and didn't understand plant growth. Evergreens should not be pruned to bare wood and any hedge pruning always should follow the "A" shape, which means narrow at the top and broader at the base to maximize sunlight penetration. You may think about legal action or reporting them to the Canadian Better Business Bureau. From a horticultural standpoint, you are pretty much out of options. The only thing I can think of is to plant another evergreen shrub in front of the existing hedge to cover up the bare area.
Q: I planted a row of evergreens under some power lines about 20 years ago. The trees are about half way from touching the lines, which is a safe distance for trimming. I read that spring is a good time to cut off the leader. This should slow down growth and get the trees to start bushing out. Should I wait until new growth starts before cutting off the leader or should I trim now while they are still dormant? How much of the leader should I cut off, but still have the trees look good? (e-mail reference)
A: I assume you are writing from somewhere in the northern part of the U.S. because you say the evergreens are dormant. Cutting the leader back will result in a bushier plant. I would suggest cutting out less than you think you should. You can go back and trim more if you don't get the results you want. Now would be a perfect time to do the trimming.
Q: I noticed a few branches on one of our evergreens have turned red. Could it be due to blight? What can I do about it? I would hate to lose it. I enjoy reading your column. (e-mail reference)
A: I appreciate you being a loyal reader. I can't say for sure, but at this time of year, I would suspect that the discoloration is due to winter desiccation. It may or may not come back after spring finally gets here.
Q: I have an evergreen in our front yard (see picture). I would like to put a flower bed under it, but I have a few questions before I start. I've heard that some trees have shallow roots and digging around the tree to plant flowers can hurt the tree. There is a root running above the ground. There isn't much grass growing under the tree, so I'm wondering if it'll sustain any kind of plant life or is it too acidic? We have very sandy soil. Thanks so much for your time. I always enjoy reading Hortiscope. (McVille, N.D.)
A: Cut a few more feet of limbs from the bottom of the tree and you will be able to plant all the flowers you want. With a tree the size of yours, the surface roots will be damaged somewhat, but it won't be lethal. I have seen plenty of attractive flower plantings under huge spruce trees with no ill effects on the tree or flowers. Thank you for being a regular reader of Hortiscope and the nice comment about it!
Q: I have some evergreen-type shrubs growing on a hill in front of my house. The shrubs look very nice after I get all of the grass and weeds pulled out, but it is a lot of work. I was wondering if there was a weed and grass killer that I could use to make it easier on me, but without killing the shrubs. (e-mail reference)
A: Once you get the weeds pulled, you can apply a product, such as Preen, that will control most of the weeds without harming the evergreens. Visit the local garden store in your area and you'll find several products on the market. Be sure to check the label for evergreens and closely follow the dose guidelines.
Q: I have two small evergreens that I planted at the same time. One is doing great, but the other is brown and dying. However, the dying evergreen has what appears to be new needles growing now that spring is here. Is there a chance it will come back or should I give up and replace it? (e-mail reference)
A: I'd give up and replace it. You may be witnessing a last gasp of growth with spring's arrival. Even if it does live, it never will be anything to be proud of.
Q: I planted an Austrian pine years ago. It grew nicely last year and looks ready to do even better this year. While researching its potential pests, I discovered it is not considered hardy for our area. Have I just been lucky the past two winters? Also, are rabbits much of a pest to this particular pine? I've had it protected, but as it is growing nicely, I'll have to expand the protection or just let it fend for itself. We sometimes do have a rabbit or two in the area. (West Fargo, N.D.)
A: You got the wrong information because it is hardy to zone 3. With climate change, that will improve. Enjoy and don't worry!
Q: I have a bunch of pine trees that have pine wilt. I am going to cut the trees down to stop the disease. I am planning or wanting to go to a friend's pasture to dig up some eastern red cedar trees to replace the pines. How large of a cedar can I dig up without too much trouble? I am of the understanding that they have a substantial tap root. How big would the tap root be in respect to the tree? This might give me an idea of how large of a tree to go after. (e-mail reference)
A: I have no idea. Why not dig up some smaller trees to see what the size of the tap root is? In any tree transplanting operation, the chance of greater success stays with the smaller individuals. The smaller trees will establish faster and grow with greater vigor.
Q: I planted ponderosa pines this spring and was told to put sacks over them for the winter. Should I do that? What can I do to get the most growth out of these trees? (Fargo, N.D.)
A: The sacks are not needed because ponderosa pines are native to our state and should do fine unless they have been grown too softly (too much water and fertilizer).
Q: I have some scotch pine trees planted in sandy soil. I noticed the interior needles are browning and falling off. During the summer, the edges of the leaves on my quacking aspens turned brown and developed a slight curl. Also, I had a large portion of my yard turn brown and die. Are these symptoms the result of disease or the dry conditions? (Carrington, N.D.)
A: These are the result of the heat and drought the region went through this past summer. This will not be lethal to the trees, unless drought conditions are repeated several more times.
Q: We have a large garden with evergreens around the perimeter. We shrunk the garden to allow for a buffer zone between the trees and garden. The roots of the trees have started to grow into the garden, which is reducing plant production. We dug around the perimeter of the garden and broke off the tree roots, but they keep growing back. A friend suggested we use copper sulfate at the edge of the garden to discourage the trees from rooting. Is this an appropriate use for copper sulfate? Will it harm our garden plants? Do you have any suggestions for a better solution? (e-mail reference)
A: Tree roots know a good thing when they find it, so they will keep coming back for the good aeration, water and nutrients in the garden. Your friend is almost right in saying that copper screening would do the job. A product called BioBarrier will keep the roots at bay, supposedly for more than a decade. Straight copper sulfate might migrate to the garden plants. While copper and sulfur are essential plant nutrients, the dose would be toxic to your garden plants.
Q: Is it possible to plant hostas under evergreen trees? Is there any type of ground cover that works under evergreens? Thanks for the information. (e-mail reference)
A: Planting hostas under evergreen trees happens all the time. Depending on where you live, so are many other ground covers.
Q: We want to plant some evergreens to block the view of our neighbor’s backyard. A recent catalog talked about Eastern white pine as a fast-growing, Zone 3 hardy tree that can grow in dry or wet conditions. I don’t remember seeing these evergreens at our local nursery. Would you recommend this evergreen? Also, we have heard of mothballs sprinkled around the base of broccoli or Brussels sprouts to keep white butterflies away. Would you recommend this? If used around the base of kohlrabi, would the kohlrabi taste like mothballs? (e-mail reference)
A: How I wish the white pine would make it in North Dakota! White pines are among the most beautiful trees in North America. Catalogs have a tendency to "stretch" the facts a little, so what they say has to be carefully weighed. Arborvitaes are the brick-and-mortar plants for what you want in our area. When properly planted, arborvitae will thrive for a long time. They often succumb to being planted too deeply or overwatering. I encourage you to communicate with the garden center. It is not going to sell you something that is not hardy to your area! Mothballs are a bad idea because they are extremely toxic! I routinely see mothballs used by well-meaning homeowners for the control of squirrels, voles and raccoons, but it doesn't work. What mothballs do is pose a danger to anyone downwind of the fumes. Long-term exposure is chronically toxic to warm-blooded animals. That's you and me. The worst part is that, after awhile, your nose is desensitized and you no longer detect the distinctive odor. The distinctive odor that is overpowering to moths in an enclosed environment, such as a clothes bag, is naphthalene, p-dichlorobenzene and camphor. What is unique about mothballs is the ability of the chemical components to penetrate just about anything except a Fort Knox safe. Any other use is considered unsafe and off-label, which is against the law. Frankly, I wish the EPA would put mothballs on the restricted-pesticide or repellent list! Cabbage and other members of this family of cruciferous plants can have the cabbage butterfly (either the imported cabbageworm or the cabbage looper). The butterflies are controlled by using a safe biological material known as Bt (Bacilllus thuringiensis). The butterflies still will appear and the females will lay their eggs, but when the young hatch and begin feeding, they get sick and die. You also can use Sevin insecticide, which kills them outright upon feeding. Both products need to be reapplied through the growing season.
Q: I have a young, potted Norwegian spruce as a Christmas tree and wish to keep it alive. I have noticed that it is starting to drop many needles. The soil is damp. I have it indoors because I have nowhere to put it outside for the moment. It is near a window, so it gets plenty of natural light. I try to keep the room at an average temperature of 20 degrees. Is this too warm? (e-mail reference)
A: You are killing the tree with human kindness. Norway spruce need the cold to survive. Get it outdoors and into the ground or surround the pot with snow and straw. There is no way it will survive where you now have it. Potted, temperate evergreens used as Christmas trees need to spend as little time indoors as possible.
Q: My driveway sits under a large long-needled pine tree. A few months ago, I started noticing tiny blobs of sap on my car, which are difficult to remove and are ruining the paint. I cleaned the car and purchased a car cover (very cumbersome). At the risk of sounding silly, will this tree drop sap year-round or is there a sap season? It would be nice if I didn't have to cover the car all the time. (e-mail reference)
A: I would suggest that you contact a tree specialist to find out why the tree is dripping sap in such quantities. The cause could be canker disease or borer activity. If you live in the North, where winter temperatures remain at freezing or close to it, you shouldn't have to worry about sap flow problems during the whole year.
Q: How do you propagate a Chinese evergreen? A piece of a friend's evergreen broke off and I would like to start one of my own. It has a good stalk on it. I have it in water, but the bottom leaves are turning yellow. Can you help me out? (e-mail reference)
A: Get the broken piece out of the water and make a fresh cut across the base. Remove the yellowed leaves and stick the piece in a mix of sand and sphagnum peat moss. Keep the soil damp. It may root for you in a couple of months.
For more details, go to www.ext.nodak.edu/extpubs/plantsci/landscap/h1257.pdf.
Q: I recently moved to a property that has some large pines (red). The trees are surrounded by railroad ties and filled with soil. The soil goes a couple of feet up each pine's trunk. I know this eventually may kill the tree, but will removing the ties and the soil be too shocking to the tree if done at the same time? (Ely, Minn.)
A: It will be as "shocking" as pulling a person from a drowning situation at the very last minute! Get on it as soon as possible. Hopefully, you will have acted in time.
Q: I subscribe to putting trees to bed wet in the winter but the Oct. 5 snowstorm carried things a bit too far. We have a beautiful Scotch pine in the back yard. The top third broke from the weight of the snow and wind. Will it recover and is there anything we should do to help it recover? As usual, we value your advice. You haven't steered me wrong yet. (Turtle Lake, N.D.)
A: Glad I haven't steered you wrong! For now, there is nothing that can be done to help the tree recover. The Scotch pine should recover, but it might have a slight crook in the stem as a new leader takes over. I assume you made a clean cut of the break. If not, do so.
Q: I have a question about transplanting Norway pine seedlings. My daughter and husband bought a home on a former tree farm. They have many seedlings, so we would like to transplant some of them. What is the best way to transplant the seedlings? Also, how do you start pine trees from pine cones? (e-mail reference)
A: Push a straight-edge spade into the ground, pull horizontally on the handle to open a hole, drop the seedling in and pull the spade out. The soil should flop down on top of the roots of the seedling. Gently step on the soil plug to make firm contact with the roots. I did it for two years for a Christmas tree grower in New York state. Put paper bags over the cones before they open up to collect the seeds. After the seeds are collected in the bags, plant the seeds in the fall for possible (and probable) germination the following spring.
Q: I transplanted about 10 evergreen trees four to five years ago. They are now about 10 to 12 feet tall. They get watered at least three times a week. A few weeks ago, I noticed a tree was turning brown and appears to be dying. It does have some green needles, but I would guess 85 percent of the tree is dead. What would cause this and can the tree be saved? (e-mail reference)
A: Evergreens as tall as yours come nowhere close to needing water three times a week. I’m surprised that more of them are not dying. Shut the water off and allow the roots to forage for the water themselves. The best I can do is guess about a tree that is 85 percent dead. I’d say the answer is no, it will not survive. I suspect that root rot has set in and is causing the decline.
Q: We would like to plant thuja evergreens, but don’t know if they will survive in our climate. When is the best time to plant? We have tried evergreens before, but without luck. (Lehr, N.D.)
A: This cultivar very likely will turn bronze during the winter, but survive nonetheless. Be sure you give them plenty of room to mature, don’t plant them too deeply or overwater and be sure to spray them with Wilt-Pruf just before winter closes in.
Q: We have two very healthy bull pine shrubs. Can I start a new shrub from a branch or should I wait for the cones to mature and then plant the seeds? (Rugby, N.D.)
A: Ponderosa pine can be propagated using the cones (actually the seeds in the cone). Place a bag over the female cones after fertilization has taken place to keep the squirrels and birds away from them. Plant immediately after they drop into the bag because they have no chilling dormancy requirement.
Q: What causes evergreen tree needles to turn brown? It is especially bad on the south side. Is this a lack of moisture or do they lack an element, such as iron? (Faulkton, S.D.)
A: The browning of evergreen needles is due to the loss of moisture from the winter sun. The green color of the needles heats up beyond the ambient air temperature and the frozen soil cannot send water through the root system. The stomatal pores open, the moisture vapor leaves the needles and eventually is depleted, and then the needles turn brown. Often the buds are not adversely affected and the plants will regreen on the browned side. This problem is common on young trees, especially if they were planted recently. It can be prevented by spraying the foliage with an anti-desiccant, such as Wilt-Pruf, prior to winter’s arrival and again in late winter during a thaw when the temperature is above 40 degrees.
Q: I bought a ponderosa pine and was told not to disturb the roots when planting. It is in a wooden basket-type pot. They said to take the bands off and cut off at least the top half or more and leave the rest. It should then decay and not disturb the roots. Is this a good way to plant it? (e-mail reference)
A: It happens all the time and with success, too! If you can peel or pull the sides of the basket back and leave it that way, it also would help. The wood breaks down quickly when it is surrounded by soil.
Q: Can you tell me how to save my aglaonema or “silver bay”? There are several firm, green stalks, but the leaves have died off. I believe they were sunburned. I’d like to find a way to get leaves on the stalks again or else I’m afraid it will die. (e-mail reference)
A: The Chinese evergreen is one of the premiere shade-loving plants. All I can suggest is to remove the remaining leaf stalks and maintain the plant as if it still had leaves. Keep the plant in subdued light, not direct sunlight. If no new leaves emerge in six weeks, then the plant likely is shot and should be dumped.
Q: I had a producer ask about evergreens that appear to have a lot of winter injury. The evergreens are on the edge of town, so they are very visible. He is wondering about using a liquid fertilizer to spray on the foliage. I told him that I would be scared of burn. I suggested Mir-Acid, but he says he has too many trees to use Mir-Acid. He feels liquid fertilizer would have the same effect. I think liquid fertilizer is mainly nitrogen, while Mir-Acid has many other nutrients in it. (e-mail reference)
A: He does not need to spray the trees with fertilizer to get them to recover. He is better off allowing nature to do its own repair work. If they are going to recover, they will do it without extra nutrients being applied. Spraying with a nitrogen-rich material may stimulate too much growth, subjecting the evergreens to increased insect and disease problems. I have seen mountainsides covered with evergreens with the same problem. When I passed by them again two months later, most had greened up without any human intervention. He’ll probably spray anyway because most people are stubborn about this.
Q: I have a mugo pine bush that is out of control. It is 6 feet tall and about 8 feet wide. Can I trim it down a lot, part way or will the bush die? In addition, can I now trim my apple, linden and oak trees? (Valley City, N.D.)
A: Now is a better time to trim your apple, linden and oak trees. Prune the mugo pine to a lateral branch or where needles exist. Pruning beyond that point will leave a stub with no needles.
Q: I am looking at planting a row of evergreens for a windbreak and privacy hedge. The soil is heavy clay and shale rock. I have seen an advertisement for a thuja green giant, which I believe is an arborvitae. It’s said to be a fast grower and adapts to all soil types. Have you had any experience with this evergreen or would another variety, such as Canadian hemlock or American arborvitae, work better in my soil conditions? (Dickinson, N.D.)
A: I would encourage you to contact Jerry Larson, former NDSU Extension Service agent, or Craig Armstrong, Dickinson city forester. Craig has a lot of experience dealing with plant materials in your area and would be in a better position to give you advice. The green giant cultivar of the T. plicata may be a worthy contender for your site, if you can propagate stock locally (within zone 4). Keep in mind that this is the borderline for thuja green giant hardiness, so you might be better off going with one of the American arborvitae cultivars. This is where Craig or Jerry could help you make a final decision better than I can.
Q: I have a Norfolk Island pine tree that I got for Christmas last year. It was in a small pot and about 5 inches tall. It grew great all year, so I put it in a larger pot a few weeks ago. The tree has three trunks. I didn’t separate them in the new pot, but they seem to be doing well so far. Should I have separated the trunks? Do they always lose their lower branch set as a new one opens on top? This one hasn’t, but those I’ve had before did. They look like a top-heavy palm tree. I would like it to stay green all the way down. Is there a secret to it? (e-mail reference)
A: The secret is humidity, something that most American homes lack, especially during the winter months. It will help if you mist the plant regularly during the stressful, desertlike interior air we have in the home during winter. If you can, add a humidifier to the room where the trees are planted. A humidifier will keep the plants from loosing their lower branches or foliage. I would have separated the trunks, giving each a new container and fresh soil. Keeping the trunks as one will cause the roots to graft together eventually. You may see stunted growth and unavoidable damage in future repottings and possible separations.
Q: I have a very tall pine tree that has lost a lot of needles. What I am noticing in this season is a browning of needles on the lower branches or bottom of the tree and bare branches here and there on the tree (not just on the inside). I have read about needle cast disease on your Web site and it seems that this tree may be suffering from this fungus. The backside of the tree nearest the house is really bare at the bottom. I hope this condition doesn’t work its way up the tree. I read that trees should be sprayed in June and July, so it would be too late now. Should I use products such as Bravo or Dithane? Also, I checked for spider mites and didn’t see anything. (e-mail reference)
A: You are correct on the products to use to control needle cast and equally correct on the timing. Please keep in mind that with many pine trees such as Ponderosa and Scotch, it is a normal characteristic to have the trees lose symmetry as they age and drop needles on the lower branches. Be sure it is needle cast you are spraying for or else it is a waste of time and money. Send a sample to the plant diagnostic lab at the land-grant university in your state or get a certified International Society of Arboriculture arborist to check the tree.
Q: We lost nine evergreens to needle cast and will lose another 12. We destroyed the nine but are hoping to replace them with other trees. One nursery told us not to plant evergreens again because they will get the same disease. Another nursery said there was only a certain kind of evergreen to plant. Do you know what kind of evergreen to plant or should we plant something else? We cleaned up the area where the nine evergreens were, but the nursery said the fungus is still in the ground. (Valley City, N.D.)
A: Colorado blue spruce is the most susceptible species to Rhizosphaera needle cast. All other spruces (Black Hills, Norway) are less susceptible as are the pines (Scotch, Ponderosa). If you want a non-evergreen conifer, consider a larch-larix decidua. It is underplanted in our region and flushes out with fresh growth every spring.
Q: Two young evergreens have had the top leader snapped off. What will happen to the tree and can anything be done to promote the growth of another main leader? (Dickinson, N.D.)
A: The evergreen will go through a “competitive factor” now that apical dominance has been removed. You can break off all but one lateral branch or wait to see which one naturally takes the lead. Once a leader has been established, prune the others back and stake up the natural leader for a growing season.
Q: I have a Norway that is about 12- to 14-feet tall. We had a very dry spell in early spring, so the needles started to turn brown. I did put some water on it, but even more needles turned brown. There is a blue spruce very close to it and several other pines in the yard. The Norway is the only one turning brown. (Buckus, Minn.)
A: The reaction to your watering is normal after a dry spell. I would suggest giving it a weekly watering (along with the other evergreens) as long as there is insufficient rainfall. Soak the soil completely. As long as the new growth is not dropping, all should be well.
Q: I’m hoping to get a second opinion on a couple of tree questions. The first tree is in the town of Hettinger. It is a large tree in the front yard and gets watered frequently by the sprinkler system. The tree is losing its needles from the inside out. The inner most needles are brown and have fallen off; others are turning yellow. The new growth doesn’t appear to be affected yet. I believe that it is rhizosphaera needle cast, but I can’t find spores on any of the needles when I look at them under a microscope. Am I missing something? I recommended that the owner treat the tree with Bravo. I also pointed out that the sprinkler is probably making it worse by spreading the spores. The second question is about a younger spruce tree. The new growth looks good, but the tips are turning a reddish brown color. This was first noticed about June 22. We had a hard frost on June 17. Is it possible that the tree could be showing signs of frost damage? (Hettinger, N.D.)
A: You are correct in your assumption about the sprinkler’s impact. The spores would not be showing yet, but would be there in early spring. As for the spruce with the reddish brown tip growth, this could very well be the effects of the frost on June 17. The tree should be fine, just set back a little.
Q: Someone I know has brown spots on her evergreen shrubs. In the past she used Miracid, which solved the problem. She says Miracid is no longer available. Is there another product she can use? (Dickinson, N.D.)
A: In large, national department stores there are off label formulations of basically the same products as Miracle-Gro and Miracid. She should get satisfactory results using them.
Q: We have two rows of evergreens on the north and east edges of our property. In the past few years, we have been noticing that the needles, especially on the north side of the trees, are missing almost halfway up the tree and on the inside branches. Is this needle cast or some type of blight? What can we do about it? I have been reading that they can be sprayed with a fungicide, but timing is important. What is the right time and what fungicide do you recommend? My husband is afraid we will lose all the trees. (Lamoure, N.D.)
A: There is no way to tell for sure if what you describe is needle cast. Send a sample to our plant diagnostic lab. The address is: NDSU Waldron Hall, Fargo, N.D. 58105. Be sure to also send some healthy branches. The diagnostician needs to see where the pathogen is active. There will be a nominal charge for the lab work.
Q: Is it possible to plant evergreen trees from pine cones? (e-mail reference)
A: Only if you collect the seed out of the cones before the squirrels and birds get to them.
Q: I have some long-needled pine trees that are 20 or more years old. I'd like to trim the bottom branches to four feet above the ground so it would be easier to mow around them. Will it hurt the trees? Is there a better time of the year to prune them? (e-mail reference)
A: It won't hurt them, so go ahead and prune them back to the trunk.
Q: We took down a huge evergreen tree in our yard and we would like to fill in the space with some shrubs, flowers and grass. We are wondering if we have to add something to the soil before we plant. (Napoleon, N.D.)
A: Just rake the soil and plant!
Q: I have two-year-old evergreens that were planted by the Soil Conservation Service. Some have brown needles on them. I was told there is spray for infected trees, but it has to be used this month. Do you know what the spray is and where I can get it? (Ypsilanti, N.D.)
A: I doubt your young trees are suffering from needlecast disease. More likely it is the result of winter weather stress. If it is needlecast disease, you should purchase some Bravo (Chlorothalonil) to control it. Apply it now and again in July.
Q: I have an area under some evergreens (cedar and spruce) where grass won’t grow. I tried all kinds of grass seeds with no results. There is enough sun. What am I doing wrong? (e-mail reference)
A: Rake off all the needle litter down to the bare soil. Then take a little lime and rake it into the soil surface. Use about 1 kg per 93 square meters. Bring in enough fresh soil to cover the area about 10 centimeters thick. When planting, use a mixture of Kentucky bluegrass and creeping red fescue.
Q: We have a long row of spruce evergreens that run east to west. They are 12 to 15 years old so they are well established. This past winter was evidently hard on them as several have developed very brown needles. I was informed that, if it is a disease, we might have to remove them. That would be sad as it takes so many years to get to that size. I would appreciate your thoughts or suggestions on this problem. (Tower City, N.D.)
A: I would suggest waiting to see if you get new growth in the next month or so. It is likely winter damage but, if the evergreens are well established, they will not succumb to this past winter's harshness. You can check the buds and see if they are still green (use your thumbnail to break into them). If they are still green, new growth will emerge later this spring and eventually the burn you are seeing will disappear. You might want to water them once a week to help them along if we continue to go without sufficient rain.
Q: I’m having a problem with a white pine tree. It was planted two years ago. Last year it had new growth but also lost many brown needles. We hose them off throughout the summer. Now they are looking very rusty. (Minot, N.D.)
A: It could be winter damage, so it may recover. Contact Mike Rose, your local county agent, to see if he can help you.
Q: I planted two ponderosa pine trees late last fall. They were in nice shape but in mid-winter they started turning brown. Should I have sprayed them with a defoliator? Will they survive? The needles are still bendable. (E-mail reference)
A: Never use a defoliator. Instead, use an anti desiccant like Wilt Pruf. The trees are showing some moisture loss from winter stress. I'm confident they will survive.
Q: I planted two ponderosa pine trees late last fall. They were in nice shape but in mid-winter they started turning brown. Should I have sprayed them with a defoliator? Will they survive? The needles are still bendable. (E-mail reference)
A: Never use a defoliator. Instead, use an anti desiccant like Wilt Pruf. The trees are showing some moisture loss from winter stress. I'm confident they will survive.
Q: I have a Christmas tree question. We cut trees off my parents land every year for a Christmas tree. This year the trees were so tall that we cut the tops off for each of our homes. They are spruce trees. To our surprise, they have new growth coming out. Are they alive? Can they be transplanted or put in dirt and actually grow? We have kept our tree up until we can find an answer. (E-mail reference)
A: No, they are not "growing." The buds have simply had their chilling requirements met, and are breaking dormancy, extending to the extent of the energy reserves in the material that you cut off. I wish it were that easy to propagate spruce trees.
Q: A friend from Badger, S.D., asked me to write a note and ask for your advice about some evergreens in their yard. She cut a few branches off to make a wreath, but says they are so dry the needles fall off about a foot from the end and all the way back. She thinks they are much drier than they have ever been before and wonders if she could water them at this time of the year or if there is anything else she should do. (Bruce, S.D.)
A: You can water if the soil is not frozen. She might also want to spray the trees with an anti desiccant such as Wilt Pruf, as long as the air temperature is above 40 degrees.
Q: Can you give me a little info on hemlock? I read it can grow to 40 or 50 feet high. Is that right for a full grown evergreen? We don't want anything that gets that tall. We have a house next to ours and don't want the root structure to interfere. It is not too close, but just in case we want to be safe. Let me know a little about it if you could. (E-mail reference)
A: True Canadian hemlock will eventually get that tall. They are beautiful evergreens that slowly grow and maintain a graceful, somewhat weeping architectural form. Un-pruned arborvitae will also come close to that height. Neither plant has what is considered an interfering root structure. The choice is yours, depending on local availability and price.
Q: Do you have any information on princess pine? It is the evergreen like plant that greenhouses use in floral arrangements, especially this time of year. I have no idea if this common name is even correct. (Bottineau, N.D.)
A: I think you mean reindeer moss or club moss. They sometimes make wreaths out of the stuff and use it in arrangements depicting Christmas or winter scenes. That's the best I can come up with.
Q: I found a couple ponderosas in my shelterbelt with small holes in the new growth candles. The candles curled over and dried up. Is this a problem that I need to take care of? (Onida, S.D.)
A: The holes in the candles indicate either beetles or borers are feeding. I would suggest spraying the trees before bud-break early next spring with Orthene to help control whichever pest this is. Be sure to monitor your trees next spring as growth commences and take additional action as necessary. Another possibility is that the curling could be caused by phenoxy herbicide drifting in at bud-break time. If you are involved in spraying crops to control weeds or if a neighbor is, take all the necessary precautions to prevent this from happening. If you think this is the case, then the insect damage may just be a secondary problem.
Q: I have some evergreen shrubs on the east side of my house that need to be trimmed so they don't block the picture window. Can you tell me, from the sample I’ve sent, the name of the shrub, the proper way and time of year to trim them? (Tyler, Minn.)
A: The sample you sent is an arborvitae but it is impossible to tell which one. They should be pruned in early spring, prior to any new growth. When you prune, do not leave a bare branch. Always leave some green foliage right below the cuts. That is where the new growth will be generated. To encourage dense growth, I would suggest giving the plants a shot of fertilizer such as Miracle Gro or something similar.
Q: There is a row of huge pine trees that are planted along the perimeter of a cemetery. They are planning to prune the bottom of these trees 5 to 6 feet up. Will pruning harm the trees? The surrounding homeowners are concerned that this would be the wrong thing to do to these beautiful trees. (Vermillion, S.D.)
A: It will not hurt the trees in the least. What the homeowners are complaining about is the destruction of the natural shape and beauty of these majestic spruce trees. If they pose a security or safety problem and pruning will rectify the problem, then I would point that out to the homeowners and go ahead and prune them.
Q: I grabbed the wrong container and sprayed all my evergreen trees with Roundup. The evergreen trees are alphaviders. Will the Roundup kill the trees or just drop the leaves? I also sprayed some of the bottom limbs of my cypress tree. (E-mail reference)
A: I don't know if it will kill the trees. There isn't much you can do about it now except wait and see. You should know the results in about seven to 10 days depending on the temperatures where you live.
Q: We are losing evergreens and are wondering if you can help us. The trees vary in age from five to 15 years old. The needles turn pink, then brown and then fall off. We have checked for spiders and sawfly but didn't find any. These trees are sprayed every year with Malathion or Sevin. (Powers Lake, N.D.)
A: I'm certain the evergreens you are referencing are spruce. They usually suffer from needle cast, which is a fungal disease. Using an insecticide will not solve your problem. Spray them with Bravo, which is a fungicide. It will stop the disease from spreading. Spray in June and again in July. It will take about three years to bring it under control. Monitor the trees from then on to make sure it doesn't flare up again.
Q: Four years ago I planted three Scotch pines that were about a foot tall. They are now approximately four feet tall. Last spring we experienced some major flooding in our yard. For about four weeks we had water three inches deep where the trees are located. When winter came they still were relatively green except for the tops, which were starting to turn brown. This spring all three trees had lost their needles. I remember reading once that some species of fir trees will shed their needles for a period of time. Are they dead? If they are just shedding needles, how long before they will green up again? (Buffalo, Minn.)
A: My answer is simple -- give them their last rites because they are history. Shedding of needles takes place on 3-year-old needles, not the entire tree. Pines simply do not like standing water. Sorry about the bad news - you are not the only one to write to me about the flooding in Buffalo, Minn.!
Q: We moved into a house that has two mature evergreens in the backyard. We trimmed the branches up about three to four feet. After we clean up the immense pile of needles underneath, is there anything that will now grow as a ground cover? We'd prefer that rather than decorative rock or bark. (Aberdeen, S.D.)
A: Yes, it’s done all the time. Simply rake up the needles, scratch up an inch or two of the soil, bring in some good topsoil and plant to your heart's content. Plant material is more interesting to look at than rock mulch.
Q: We want to replace four 40-foot evergreens which we removed because of age and disease. I am looking for an arborvitae which will have full sun exposure, grow to a height of 25 to 40 feet and fill out to a 6 to 10 foot width. It must retain greenish color in winter months, offer good highway screening and noise reduction and be winter and most bugs resistant. I have found types of hetz wintergreen arborvitae, white pine (pinus strobus), and nigra as possibilities. (Valley City, N.D.)
A: Any one of the three would do but since you asked I'll give you my highly biased opinion. Plant the pinus strobus 'Fastigiata' if you can find it. They are beautiful under-planted trees with long graceful needles, five to a bundle. All three will need spraying with an anti-desiccant to get them through the winters, doing so in mid to late October. Be brave! Be different! Try to get some plant diversity into our region. The species is hardy to zone 3 so with proper care they can make it. They are narrower than they are wide and I don't know how tall they will get in N.D. My second choice would be the nigra arborvitae.
Q: About three months ago I purchased a beautiful Norway pine. It has three trees actually coming out of the pot. Now three months later it has started to turn grayish brown from the bottom up and the branches are falling off. What did I do wrong and is there anything I can do to save this beautiful plant? (E-mail reference)
A: The plant should have been planted as soon as the soil thawed. I suggest getting them out of the container and planted as soon as possible.
Q: Some of my evergreen’s leaves have turned brown and are falling off. My neighbor suggested I use muriatic acid because the plants are being infected by insects. Would muriatic acid work? (E-mail reference)
A: I don't know where people ever got the idea that hydrochloric acid is good for evergreens. I have never seen any research to support this claim. It is a little early for evergreens to be infested by insects. Even if they are, muriatic acid is not an insecticide. I don't mean to sound like I am picking on you - I'm not, but I am writing this for you as well as others who may be thinking of asking the same question. There are lots of maladies that can mimic the symptoms you describe. I’m guessing from your e-mail address that you are in Ontario, Canada. I would suggest that you contact the horticulture department at the university in Guleph. Send them a sample or have someone in extension come out and check the tree to accurately determine what the cause could be. The problem could be winter desiccation, drought response from last summer, needle cast, canker or (hopefully not!) more than one of these maladies.
Q: Last year I asked you how and when to trim mugo pines but I lost the answer. I live in southeastern South Dakota. (E-mail reference)
A: Prune the new growth approximately 50 percent as it unfolds. If you want to reduce the size, then cut back to where there are still some needles or completely back to a lateral stem or branch.
Q: We are planning to move some evergreens in our yard this year. They are Colorado blue spruce and balsams. When is the best time to do it? The trees are at least 10 years old. (Jamestown, N.D.)
A: The best time is as early as possible for digging a rootball. If you are planning to do this yourself, you have a monumental job on your hands. I suggest recruiting some professional help.
Q: We have an evergreen which we are quite certain has needle cast disease. Can this tree be saved and with what type of treatment? (Minot, N.D.)
A: It can be saved but I would suggest that you contact Mike Rose, the Ward County extension agent. He is a sharp horticulturist and can confirm whether or not it is needle cast that is devastating your tree. If it is in the early stages, corrective action can be taken; if it is in the later stages, it may be too late.
Q: I planted ten evergreen arborvitae along a fence line for privacy about three years ago. The first year one died, but I replaced it. The second year they all took off. Coming out of this winter, all the plants have massive interior leaf loss. The exterior of the plants have a hint of brown. The tops were also fanning out so I bound them with some twine to straighten them. Did they not get enough water going into the winter? We had a drought followed by a brutal winter. Can they be saved? Is there such a thing as too much water for them? (E-mail reference)
A: Interior foliage death is not unusual considering the weather conditions leading up to the winter. As long as the exterior portion of the trees are alive, they will prevail. The hint of brown is normal at this time of year. Just don't allow them to become drought stressed this coming growing season, and equally important, don't drown them in water either!
Q: I am trying to find an evergreen that likes moist soil. I’m planting a wind break by a pond but am not sure of what type of tree to plant. Can you help? (White Bear Lake, Minn.)
A: Arborvitae, white spruce, black hills spruce (variety of the white) and balsam fir. That's about it!
Q: I have a two-story-tall evergreen tree growing near my house. I want to remove it because I worry the roots may penetrate the foundation of my home. Is my fear valid? I have heard horror stories about roots cracking foundations. Once I cut down and remove the tree, will the roots continue to grow into the foundation? I must admit I am leaning toward removing the tree if there is even a chance of major damage. (E-mail reference)
A: Trees are good if they are providing a service, but when they become a liability, they should be removed. I would worry more about the aerial part of the evergreen than the root system. Roots will grow only where they can and need a balance of air and water to do so. Unless the foundation of the house has cracks and leaks, it will not grow into the foundation while the tree is whole or after it is cut down. I suggest getting a competent, certified arborist out to examine and remove the tree and stump completely if the tree is too close to the house and would cause property or bodily damage if it should become a windfall casualty. Be sure the individual has liability insurance and ask for references.
Q: We have evergreen shrubs that have been in front of our house for about 40 years. We would like to move the plants but are afraid it may damage our foundation. We are also concerned that moving the shrubs might make a dry basement wet after all these years. (E-mail reference)
A: It shouldn't be a problem unless you don't have any roof overhang with gutters and the grade goes toward the foundation instead of away from it.
Q: I have a Norfolk Island pine tree that is four feet tall. Please tell me how to repot it in a much bigger pot so hopefully it will grow to seven or eight feet tall indoors. (E-mail reference)
A: Get the next size container for repotting. Then get some good potting soil that is high in organic matter that is labeled either "sterilized" or "pasteurized." Spread out newspaper and carefully knock the plant out of the pot by having one person hold the pot upside down and knocking on the bottom with the heal of their hand, while you hold your hands over the top of the plant to catch the soil ball as it comes out. This will work better if the soil is slightly moist. Estimate how much of the potting soil will have to be added to the new container, place it within, and carefully set the rootball in the new container so that the top of the ball has about a 1-inch lip of pot around the edge. Carefully place the potting soil around the edge of the rootball and the container, water in, and add more if the soil settles. When finished, set the plant back in the same location it was prior to planting.
Q: Can I take a clipping from our North Carolina fir Christmas tree that we bought for the holidays? We hate to lose it since it is such a beautiful tree. (E-mail reference)
A: If one could only do so! I'm sorry, but it’s not likely simply because the tree was harvested in October or early November for the holiday market and they do not root easily from cuttings. Nice thought anyway.
Q: On Dec. 6 I heard the end of a discussion about Norfolk pines on Prairie Public Radio. You mentioned something about a Norfolk pine in New Rockford. I missed the part about where it is located in the city. Could you tell me where it is? Is it growing outdoors? If so, I would like to see it. I have two Norfolk pines as houseplants. They are about 12 years old. They are doing well but I have never repotted them and rarely fertilize them. Occasionally a branch will dry up and fall off but there is usually new growth on the top. Should I repot them or leave them since they seem to be thriving? (New Rockford, N.D.)
A: That particular Norfolk island pine is (or at least was) located in the county courthouse. I would be loathe to do anything to the pines you describe. I am afraid that they would react poorly and you would be disappointed. If they are doing well under present conditions, I'd leave well enough alone.
Q: We take our Christmas cactus outside and place it in the shade under a spruce tree. The plant is watered only occasionally and left outside until just before frost. We then take it back into the house, water it, hang it in the light and it starts budding right away. I can't figure out how to get it to wait at least until Thanksgiving. If they don't bloom, I can get a new one for $2. I was given a Norfolk Island pine. It's over three-feet tall. Over time it lost all its branches except the top two which are showing new growth. Should I run or fight? If I cut the top off, will it re-root? Will the root grow new shoots? The original one we have is healthy and is over 6-feet tall. (E-mail reference)
A: Interesting reversal of the typical problem! I can only suggest that keeping it at lower temperatures. Keeping it at approximately 55 degrees F would slow down the bud development and opening somewhat, hopefully until Thanksgiving. The Norfolk Island pine can be air-layered. If you are interested in the process, send me your mailing address and I will send you the publication, Home Propagation Techniques, where it is described in detail along with other propagation information.
Q: We are using a systemic granular insecticide called Di-Sol to control pine tip moths in our ponderosa pines. It seems to control them but only after the damage is done. Is there anything that is longer lasting? This particular insecticide says that you can eat vegetables 7 to 10 days after it is applied. Apparently it doesn't have much residual effect. It is labeled for pine tip moths though. Second question, we installed 400 yards of sod and had a battle with sod web worms. I think we won after using Ortho's BUG B GONE. But now I have a few patches on the east and north side of the house that have a white coating. Is it powdery mildew? Is it fatal to grass? Will it make it through the winter? I have applied some winterizing fertilizer and the grass was looking great until the white appeared. We have had a few frosts but mainly cool nights and sunny breezy days. (Mount Vernon, S.D.)
A: Anything that is systemic and can be used on veggies can't be very potent, so I would stay away from that material. See if you can get Orthene. It is an old systemic that is quite effective at controlling scale and other insects and has fairly good residual and systemic action. Yes, that is powdery mildew but is nothing to worry about. Simply keep the lawn mowed and collect the clippings this fall. Since you fertilized the area already, it is not necessary to do so again. The fertilization will provide a gentle stimulus for some vegetative growth to help the grass outgrow the fungus.
Q: We have two mugo pine plantings on the south side of our home along the foundation. We originally planted them on either side of the air conditioner to screen it from view. Twenty two years later they are overgrown and leggy, especially after the 2000-01 winter when so many evergreens had disease problems. By now it really encroaches on the A/C and leans over the sidewalk about half of its width. They are about 7-feet high and 8-feet wide. The bed they are in is only about 5- feet deep. Is it too late in their lives to drastically prune them? Should we remove them and try again with a pruning schedule? Is this an appropriate setting for this type of evergreen? (Litchville, N.D.)
A: In the long run, you would be better off removing them, replant and then follow a regular pruning schedule. They are a good choice for this location due to their slow growth.
Q: Could you tell us why our 20-30 foot evergreens are hanging the top 12-15 inches of their tops? Some of the evergreens are growing at a slant. There are choke cherry and Russian olive in the rows beside them, but not touching the evergreens. We have waited so long to see them get that tall and now they are disfigured. (Cathay, N.D.)
A: It could be from herbicide drift. If so, they will likely pull out of it next year.
Q: I have an evergreen business in Minot and recently did some work for a lady who has been trying to get blue spruce growing for many years and is having all kinds of problems. She has about 75 evergreens that are 4 to 7 feet tall and not one of the trees has a leader and the trees look terrible. I think one of her problems is too much water. One person in the are says the problem may be bud worms. I have about 4,000 to 5,000 evergreens and have never had this problem. I have no idea what to suggest to this person. (Minot, N.D.)
A: You can try an insecticide known as Orthene. It has both contact and systemic power. The spray application should be just before buds swell in the late spring. This is a commercial product that is readily available to homeowners through most garden store outlets.
Q: I have lots of questions, in fact 37 cents worth! I read and enjoy, save and use much of your column. First, my delphiniums seem to rot from the bottom up. I've treated with Gardengard which is for bugs, snails and slugs. Could it be silver fish? Two new plants did the same in a new spot. Could this have come from the greenhouse? Should I reset them in an entirely new place? Second, I have lilies but something is boring into the stems so they get dry and brown and break off. I've treated with Gardengard which may have helped some. I remove and burn the affected stems. Any suggestions will be appreciated. Third, how can I start old fashioned roses from cuttings? I'd hoped not to have to dig up starts. I tried rooting compound and potting soil, but the twigs just dried up. Fourth, is there any hope for baby evergreens once they lose their needles? Might they come back in the spring if I continue to water and care for them? (Bristol, S.D.)
A: Here are your answers - thanks for writing and the nice comments about the column.
- Definitely relocate the delphiniums. I don't know what the problem is, but whatever it is, don't go back. Make sure they get direct sun.
- Try a systemic like Orthene.
- I’ve enclosed a "Home Propagation Techniques" publication available from our office.
- No hope - they're history.
Q: Our mugo pines are about 12 years old and are in need of trimming. When do we trim them and how far back can we cut them? They are about 5 feet tall and starting to cover the front window of our home. (Parker, S.D.)
A: Mugo pines are best pruned in the spring prior to the new growth breaking. Always cut back to where needles are present, not bare stems, or, cut back to a lateral branch.
Q: I would like to replace five evergreens which are in the corner of my yard with new ones. The present evergreens have branches that have turned brown and died, starting at the bottom and going about halfway up the trees, a process that has been continuing for the past several years (we sprayed the trees twice a few years ago). Would it be okay to replace the trees in the same location, or might the same thing happen to the new ones? Also, I have three clump birch trees in my yard, one of which is flourishing beautifully, and the other two have branches that did not leaf out, especially on the top third of the trees. They also have yellowish looking leaves in comparison to the healthy one. Is there anything I can do for those trees? (Mayville, N.D.)
A: Replacing with the same species that has died out is never a good idea. It they were Colorado spruce replace them with Black Hills spruce or Ponderosa pine. The clump birch that are showing symptoms are likely being attacked by borers, which are very difficult to control once they get started. If you can locate a certified arborist in your area, you might want to have the trees treated to prevent their further spread and destruction.
Q: Over 10 years ago we planted two parallel rows of Ponderosa pines as a windbreak/screen around our suburban 3-acre lot. We also have ash, spruce and other trees in the windbreak as well. The Ponderosas have done very well but typical of that tree they are losing their lower branches as they grow. Is there anything we can plant between the rows that would serve as a screen when the lower branches are gone from the Ponderosas? As you can imagine it is quite shaded and filled with pine needles. There is not a weed problem as they are shaded/ mulched out by the pines. (Bismarck, N.D.)
A: Would you consider deciduous shrubs like honeysuckle or lilacs? Annabelle hydrangea, currants, dogwood, and viburnum would all do well in shade. About the only evergreen you could use is the mugo pine. You will have to scrape the needles out of the area you want to plant to get anything established. When I lived in Georgia, I enjoyed walking through pine woods because of the mulch formed from the needles and the lack of any significant undergrowth.
Q: I would like to start some evergreens from seed, specifically Ponderosa pine and blue spruce. My present trees produce a lot of cones, but I'm told that the seed is gone from the cone before it falls to the ground. How can I collect the seeds and what is the best way to get the seed started? (New England, N.D.)
A: When you see the cones in the early stages of forming, note the ones you want to save. Then, after the male cones have dispersed their pollen, place a small paper sandwich bag over the cones and tie them tightly. This should be done before mid-July to be on the safe side. Then, after a couple of frosts in the fall, carefully harvest the bags. The bags should contain seeds that were dispersed. Next, determine where you want the trees to grow and plant the seed about 1 to 2 inches deep and water. Next spring, if they were viable and no one else found them for food, you should have some trees growing.
Q: Is there a systemic insecticide made for borer control in pines that could be poured around the base of the tree and taken up by the tree? Are there any insecticides that would be actually taken up by the pine tree and provide control against borers? (Hettinger, N.D.)
A: The systemics are not effective against tree borers. They are costly, expensive, have a potent LD-50, and give only variable results even when professionally applied. The control for borers is typically topical applications of insecticides like lindane and permethrin (Astro, etc.). Chlorpyrifos (Dursban) is now illegal to use. The problem is timing the application just right to get an effective kill. It can vary from season to season and each microclimate change. Best bet: Select trees and shrubs that are resistant to borers; attempt to select the right plant for the existing environment to reduce stress, which attracts borers.
Q: I wrote to you last fall on how I should care for some new evergreens I planted. You said I could either protect them with burlap or let the snow cover them. I did the latter, but as you know it was kind of a bad year to let the snow protect them! I have two staggered rows of trees on the south side of the property (the trees are about 2 feet tall) and in between the rows (the rows are about 10 feet apart) we put up snow fence. Most of the wind we receive comes from the south with no protection from the wind, as there are fields across the road. It seems that the evergreens south of the snow fence, basically only the south side of the tree, have turned brown, while the ones on the north side of the snow fence have stayed green. Could it be from the wind? What can I do to help the evergreens this spring? For that matter, the rest of the year? (Glyndon, Minn.)
A: Browned evergreens at this time of year is not unusual, and in 90 percent of the cases recovery is complete. There is nothing you can do at this time or later to help them out, unless it turns out to be a dry spring or summer, then supplemental watering would be called for.
Q: I have a client in here who's wondering how deep a root system a 50-foot evergreen tree has. He's wondering if they blow over easy. They haven't blown over yet through some pretty tough winds. A garage is about 20 feet away. (Linton, N.D.)
A: I cannot quantify the root mass for any particular tree for you. All I can tell you that it is extensive if the tree is healthy and the soil conditions are not adverse. Neither can I guarantee that the tree will not blow over in any future winds, even though it has survived severe winds to date. Evergreens become more prone to windfall because of the "sail effect" they present to the winds with their perpetual foliage cover, and when a high wind storm has been preceded with a soaking rain that may soften the soil enough to loosen the root system's anchoring function.
My advice: if the client feels at all leery about the tree falling on anything of value, he should have it removed.
Q: I planted a sweet potato in a flower pot. It has sprouted out all over the place and is growing fast. How do I plant it in the garden and where do the tubers grow? Also, can you stop an evergreen from growing up, up, up? (Jud, N.D.)
A: You really jumped the gun on starting the sweet potato this early! If you can keep it alive, plant the whole thing when the danger of frost is over. They will develop their tubers along the root system over the summer. In the future, simply plant the appropriate cultivar directly into the garden. I cannot accurately advise you on your evergreen question. There are pines, spruces, junipers, arborvitaes, firs, and cedars to name a few. I don’t want to give you a generic answer like "prune it" without knowing which species it is, as the timing and technique differs for each.
Q: I am a long time gardener who has enjoyed starting my own seeds. I have had good luck with tomatoes called "Super Fantastic." The last several years I haven’t been able to find the seeds. Could you give me some information on where I might purchase the seeds? Also, what kind of evergreen trees could I plant that would not harm the apple trees? (Wolsey, S.D. )
A: Tomato Grower’s Supply has the tomato seeds that you are looking for. Their phone number is (888) 478-7333. The seed is listed on page 11 in their catalog. Any evergreen would work except any junipers.
Q: We have been feeding birds (sparrows) all winter and our neighbor has complained saying that there are so many birds roosting in his pine tree at times that it is killing the tree. The birds feed twice a day, usually morning and right before dark and then disappear. Is there any truth to this? (Fargo, N.D.)
A: If sparrows have the power to kill pine trees, then the trees were not very healthy to begin with. No one could have more birds roosting in their trees (two Ponderosa pines and an Amur maple) than I do, waiting for their morning and afternoon feed to be delivered. In other words, I doubt the veracity of that statement.
Q: I currently have a pine tree located in the center of a square area of approximately 20 feet by 20 feet. Up until the night of Aug. 8, when the wind storm came through Grand Forks, this was a beautiful blue spruce tree of approximately 70 feet. While this towered over the house, we had become accustomed to the tree and could watch the birds in it from our dining room patio doors. In the storm we lost the top 45 feet or so which came down on top of the house causing some damage. We now have a pine tree that is topped at about 25 feet. Is there any hope for this tree or would it be best to get rid of it? If one were to get rid of it, what would you recommend to replace it with? If it were replaced, I would like something that would fit the space better and maybe not be as tall as the old tree, and since it is so close to the house it would need to be something that wouldn't damage the foundation with its root structure. I would appreciate your thoughts on what we might consider doing. (Grand Forks, N.D.)
A: There is no hope for the tree, spruce or pine, whichever it is. It may stay alive, but it will not be a complement to your home. I'll make some recommendations, both deciduous trees and evergreens. The deciduous tree I'd recommend is one of the many cultivars of the Amur Maple. There are at least three worth considering: Red Wing, Embers and Flame. All have beautiful red seed (aka samaras), attractive fall color, and don't grow out of scale to a home residence. I have one in my back yard, right next to the patio. We really enjoy it. Another one with interesting character, but not fall color, is the Stately Manor (a male form of) Kentucky coffeetree. The leaves are twice and sometimes thrice pinnately compound, giving a graceful appearance in summer, but the rugged bark and branching habit give it an entirely different character in winter. Finally, the Dakota Pinnacle birch is a white barked species that is borer resistant and is also compatible with residential settings without overpowering. The evergreens would be Black Hills spruce (Picea glauca var. densata), a much better adapted tree than the blue spruce; the Sentinel cultivar of the Scotch pine, or the Swiss Stone pine, a very beautiful five-needled pine. Of the three I tend to like the Scotch pine a little better because of the exfoliating red bark that develops as it matures, but the choice is yours. You won't go wrong with any of these selections.
Q: I recently purchased a Norfolk Island pine for our Christmas tree. The pot has four of the little trees in it. I have been told to separate them and transplant into separate pots, or one may strangle the others. I have also been informed that these pines do not like to be transplanted. What should I do to have a healthy plants? (E-mail reference)
A: They definitely should be transplanted, even though they don't cotton to the idea too well, as not doing so will eventually spell doom for all of them in that one pot. Using a soil-based commercially available potting mixture, replant each one in 5-inch pots this spring and water well, along with a dilute solution of fertilizer. Spread newspapers over a table or floor, gently knock the plants out of their present container, and repot at the same depth in the new containers. Gently firm the soil with your hands and water in. Allow the water to firm the soil around the roots. Be sure the new pots are free-draining. Be sure they get plenty of indirect light from a window or else the plant will lose needles.
Q: I am trying to find out about a beautiful pine tree, a Blue Ice. I do not know the proper name. I would like to know how to take the cone and start a new tree. If you could help answer this I would appreciate it. (E-mail reference)
A: I have a listing for a 'Blue Kiss' blue spruce, and an 'Extra Blue' limber pine, but have never heard of a Blue Ice pine tree. That said, taking a cone and excising the seed may not do the trick in reproducing the same color or form, as it is likely asexually propagated from cuttings or grafting.
Q: Last fall I had four bull pine (long needle) trees moved in by a tree service (transplanted from his tree grove). They were about 10 to 12 feet tall. They were staked down and watered well last fall. This spring they seemed to bud out but then stalled and eventually died and had to be replaced. The tree service person thought I killed them when I spread my weed and feed on the lawn. Is it possible that normal fertilizer and weed killer applied to the lawn would kill a tree of this size? If it is true, how far away do I have to stay with the application of weed and feed to the surrounding lawn? (Jamestown, N.D.)
A: I am going to answer your question as gingerly as possible to try not to hurt anyone's feelings.
First of all, if the tree roots were not pruned for a year or two before being moved, then about half to two-thirds of the tree roots were left behind. The tree spade will dig a ball of earth/roots about 44 to 48 inches in size. Trees the size you described have a very extensive root system beyond that. This translates into insufficient root mass to pick up nutrients and water to deliver to the tree needles, which could result in the death of the tree. Next, the "weed and feed" combination is so weak in the active ingredient (AI) that it is lucky to get weed kill, let alone kill a tree. Besides, there are a couple of weed and feed types. One that is used for pre-emergence treatment controls mostly annual grassy weeds, and the other controls the perennial broad-leafed weeds, like dandelion and plantain. If you got under the canopy of the trees with the first, no damage would likely occur. If you got under the canopy of the trees with the latter, there is a chance for damage to occur, but not likely. Notice I said under the canopy of the trees. I doubt that you did that, and I doubt that the tree roots would have grown out that far in just one growing season. My analysis of the situation is that the trees died because of root system loss, unless the tree mover will back up any claim that the tree roots had been pruned for at least a year or two before being moved. If they came from a "tree nursery" they were probably pruned on a regular basis to build a nice tight root system. If they were simply dug from a shelter belt, I wouldn't bet the family car that they had been pruned.
Q: A gentleman told me he had read that there was a spray we can use on evergreens to seal them, basically to prevent browning of needles. I'm not aware of anything that can prevent environment damages, or is there? (Carrington, N.D.)
A: Yes, there is a material known as Wilt-Pruf on the market. There are others too, but this one is most common. Basically, they all work the same way; spray goes on milky, dries clear. It cuts down on desiccation throughout the winter, which prevents browning and dying of the foliage. It is also a good idea to reapply it in late winter during one of the thaws, as that is the time that most of the damage can be done--the air is warming, the foliage is warming and transpiring, but the soil and root ball are frozen and unable to translocate the needed moisture for replacement.
Q: How do you split an African violet? I have one in a small pot and the flowers had a hard time showing up through all the leaves. Also, how do you start new ones? I have two 35-45 foot evergreen trees I planted 22 years ago and they are doing great, only I have noticed in the past two years that they have sent what looks like roots out from the tree about 4 feet and and about a half inch above the ground. Can I wack them with my chain saw and can I do it now?
This summer I bought six Coleus (Solar Spectrum) plants for around the deck. They are so beautiful I would like to bring them in the house for the winter. Any ideas? (Valley City, N.D.)
A: Take a sharp knife and cut the African violet cleanly through the crown, dividing it either in half or quarters, depending on how thick and big the crown is. New violets are started from leaf cuttings. Simply cut a leaf off the crown, with the petiole attached, and stick it in a sand/peat mix (50/50), keeping it moist, and under diffused or flourescent light. In about four to six weeks, roots should appear and a new plantlet should be visible getting started at the base of the leaf petiole. Go ahead and whack the tree roots. I have never heard of a root developing like you describe, but then I learn something new about nature every day. Go right ahead and bring the Coleus inside. You might also take some cuttings and root them in the same manner as described for African violets, except that you need some of the stem as well. Each cutting should be about 4 inches or more long. Be sure to give them plenty of light to keep them from becoming spindly.
Q: What can I spray on my evergreen trees to get rid of spiders? (E-mail reference)
A: Believe it or not, a hard spray of water on a weekly basis will do as well if not better than any pesticide that I can recommend.
Q: Can you tell me what is wrong with my Norfolk Island pine? It keeps losing branches and I am not sure if I am watering it too much or not. (Carrington, N.D.)
A: It is possible that your Norfolk Island pine is receiving too much water; however, branches are usually lost when the plant is allowed to dry out or when it is located near a heat vent or other source of hot, dry air.
Q: Eleven years ago at NDSU's centennial celebration, my mother-in-law and now husband were given a Siberian pine tree as they left the festivities. I would like some information on this tree before it gets transplanted to my yard. What are it's growth characteristics and what environment does it prefer? (Watertown, S.D.)
A: I think you must mean Siberian larch; there is no such species as Siberian pine. This deciduous conifer is a beautiful tree that needs no special care, just a place to grow. They can get over 50 feet tall, so give them plenty of room to grow. I am afraid that you are too late to do the transplanting for this year. I suggest waiting until fall when the needles have dropped off, or early next spring before new growth emerges.
Q: I had some evergreen trees moved in from single row plantings to my yard in town. A few existing large old evergreens seem to have needle cast or something similar as they are losing needles from inside to outer tips. Two or three of my large evergreens have lost about half their lower branches and it seems to be working up the tree. What can I spray them with and will it help to spray my new trees? Also, should I fertilize these new transplants, and if so with what type of fertilizer? (Wimbledon, N.D.)
A: Spray in early June with Bravo; repeat in early July with all your evergreens. A liquid fertilization would not hurt. Miracle-Gro or Miracid can be used.
Q: We are looking for evergreens for our farm yard and have an opportunity to acquire some from Ohio that we are not familiar with--Thuja plicata ‘Spring Grove’. Are you familiar with these trees, and what are your thoughts on growth success (with some winter protection) here in South Dakota? We have a deer problem here (even in our yards) and our relatives state these are supposedly "deer resistant." (E-mail reference, Miller, S.D.)
A: That cultivar of Thuja--'Spring Grove'--I don't have listed in any of my references, so it must be a relatively new introduction. Coming from a nursery in Ohio, I would say that you are safe in making the purchase for your location in South Dakota. These plants typically like moist soil conditions and will need some protection from winter's blasting winds. As far as "deer resistance" goes, it’s an easy claim to make. Just keep in mind that resistance is just that--not immunity.
Q: I have a question about winter burn injury on evergreens. Can anti-dessicants only be effectively applied in the fall right before winter sets in, or are there other times of the year that it can work? (E-mail reference, Cando, N.D.)
A: An anti-desiccant application can go on again in the late winter/early spring while the soil is still frozen. In most cases, the evergreens recover with new growth, just looking a little worse for the wear of the winter. If the warm weather continues above freezing these next few days, that would be a good time to reapply the anti-desiccant.
Q: What is causing my evergreen trees to turn brown and what can be done to prevent it in the future? I assume the harsh winter we have had is the cause, but is it the wind burning them, sub-zero temps, reflection from the snow, or what in particular? Perhaps a combination of all of the above? My Mugo pine shrub was partially uncovered and the exposed areas got brown so I covered the whole thing with snow. The Ponderosa pine in our yard is showing some brown as are many other right in town. (Britton, S.D.)
A: The needles on your evergreens are drying out--desiccating--from a combination of factors: wind is pulling the moisture out of the needles, which are warmed by the bright sunlight, but it cannot be replaced because the moisture in the soil is frozen. Don’t worry. I’ve seen many evergreens recover by late May or early June that were assumed dead in February or March. The buds, which are now dormant, will many times emerge with fresh green needles in the spring.
Next fall, put a burlap barrier around the trees and spray with an anti-desiccant before freeze-up. Re-apply on a warm day in late winter (minimum temperature 40 degrees F) for extra insurance.
Q: We are in southeastern South Dakota and I, as well as many other residents in the area, have had extensive browning (I believe winterkill) on the northwest side of Austrian, Scotch, lodgepole and white pine. I know that these needles are dead and will not be replaced, but in the cases where the entire tree is brown, is it a goner or are the growing tips still alive and will they take off again this spring? Some of the trees are large, over 20 feet, and some are small, approximately 4 feet. The smaller trees were watered well into the fall but no anti-desiccant was applied. The Ponderosa pines appear to have suffered no damage. (E-mail reference, Mount Vernon, S.D.)
A: I wouldn't write the pines off just yet. I have seen entire mountain sides looking like every pine there was a goner, to come back through in May or June to find them all green again. Winter desiccation does take it's toll on the open needles, but the buds are usually well protected by sturdy scales, and the new growth will usually emerge fully green. My advice: wait until the first of June, and if the new growth has not emerged at that time, those trees are history and can be removed. I think you'll be all right in most instances, as the trees have seen some pretty rough weather in the 20 years they have been there and have survived.
Q: I have a question about my evergreen and I wonder if you would be kind enough to help me save its life. It is about 3 feet tall and I have it potted on my balcony in New Jersey. We have had a cold winter with lots of snow so I am bit concerned that the intense dryness and brown color are a result of the roots freezing. Can you recommend something I might do to save my little tree? Or is there a point in which the tree is too dry and too brown to come back? The branches are extremely brittle and snap off when you move them around, but there is still a bit of green left. (E-mail reference, Hoboken, N.J.)
A: I am afraid it’s time to give up on your tree. Root systems are not as cold tolerant as the top, and since you have had it in the container, the roots have been exposed to the ambient air temperature, which in most cases is lethal. At this stage, there is nothing that can be done to save your tree. I suggest getting another one this spring to enjoy, then before winter dig a hole in the ground and plunge the plant -- pot and all -- into the soil and cover the roots completely. Spray the foliage with an anti-desiccant prior to freeze-up and again during a late winter thaw. If putting the plant in the ground is out of the question, then I'd suggest wrapping the container in a plastic bag that is filled with straw or leaves, again spraying it with the anti-desiccant.
Q: Do you have any clever ideas for what to do with my tree after Christmas? (Fergus Falls, Minn.)
A: Many communities will pick up the trees for recycling and turn them into chips. Another thing you might want to try is to put the tree in your backyard and place bread and suet among the branches for the birds.
Q: What is an easy way to water my Christmas tree once it's up for the holiday season with all the decorations? (e-mail)
A: It's a nuisance to water a Christmas tree once it's decorated with a tree skirt and surrounded by presents. Buy a funnel and a 3 to 4 foot length of vinyl tubing to slip over the funnel outlet. Fasten the funnel/tube with a twist-tie or twine in an out-of-the-way but reachable part of the tree. Extend the tubing down the tree trunk and into the tree stand reservoir. Now you can water the tree through the funnel without bending over or disturbing the tree skirt or its ornaments.
Q: My husband and I have the same problem each year at this time. How do we pick out a good Christmas tree? I like the short needle type, and he likes the long. Which one is best? (Detroit Lakes, Minn.)
A: First, choose a fresh tree. A fresh tree will have a healthy green appearance with few browning needles. Needles should be flexible and not fall off if you run a branch through your hand. Raise the tree a few inches off the ground and drop it on the butt end. Green needles should not drop off the tree. It is normal for a few inner brown needles to drop off.
Make sure the handle, or base, of the tree is straight and 6 to 8 inches long so it will fit easily into the stand.
Do a little research on different Christmas tree types. Some Christmas tree varieties will hold needles longer than others. Typically the long needle ones like the pines will hold their needles the longest.
Now that you and your family have chosen that perfect tree, it's time to bring it home. The following are a few tips on how to keep your tree fresh throughout the holiday season:
If you are not putting the tree up right away, store it in an unheated garage or some other area out of the wind and cold (freezing) temperatures. Make a fresh 1-inch cut on the butt end and place the tree in a bucket of warm water. When you decide to bring the tree indoors, make another fresh 1-inch cut and place the tree in a sturdy stand that holds at least a half-gallon of water. Be sure to keep the water level above the base of the tree. If the base dries out, resin will form over the cut end and the tree will not be able to absorb water, and it will dry out quickly. Commercially prepared mixes, aspirin, sugar or other additives mixed in with the water are not necessary. Research has shown that plain water will keep a tree fresh. Check all tree lights for worn electrical cords. Use UL approved electrical decorations and cords. Unplug tree lights at night. Miniature lights produce less heat and reduce the drying effect on the tree.
Q: Can you tell me what is wrong with my evergreen needles? Do they have spider mites, or why do they turn brown and fall off when it gets warm or hot out? (Scranton, N.D.)
A: The needles showed no disease symptoms -- just normal senescence. This occurs every autumn with the oldest needles on the interior of the tree. You have nothing to worry about unless the action is becoming wholesale on the tree, involving the current season's growth.
Q: In our area we have had an outbreak of little green worms on our evergreen trees for the past three or four years. We sprayed them twice last summer, but we are wondering if we need to spray this year with such lush conditions. Should we just forget it and let nature take its course? (Tioga, N.D.)
A: Nature taking its course can sometimes be fairly brutal! So I don't necessarily suggest that approach. What I do suggest is a continuous monitoring of your evergreens to see if there is a population explosion of this insect, which I believe is a sawfly larvae. If the trees are otherwise vigorous and healthy, and the population appears light, then I wouldn't worry, as natural predators will usually move in.
However, if it appears that the insects are causing heavy damage and their numbers seem to be going up without a natural check occurring, then intervene with the appropriate insecticide--Sevin. Three or four years of heavy defoliation could kill the trees.
Q: I have four large evergreen trees that were planted in 1970, but since we had all of that snow, the one on the corner is drying up a lot. Is there anything I can do to save the tree? (Arthur, N.D.)
A: It is difficult to give you a solid answer on the information provided, but I'll take a stab at it being a spruce needlecast fungal disease.
This can be controlled by timely sprays with a product known as Bravo, making applications in early June and July. I suspect the trees may also be planted too closely, and if that is the case, removal of some may help the vigor of the remaining ones!
Q: Enclosed is a sprig from one of my evergreen trees. As you can see it has some kind of "white scale" on it. Can you tell me what it really is and how to get rid of it? (Pelican Rapids, Minn.)
A: You correctly identified the problem as a scale insect.
Since the time for spraying with a dormant oil has passed (March), you can spray the trees with Malathion, diazinon, acephate or chlorpyrifos this next month when they become more active and vulnerable.
Q: I am wondering why one of my evergreen trees is producing berries while the other is not? (Gettysburg, S.D.)
A: The junipers are mostly dioecious species—male and female sex organs on separate plants. The one with the berries was female and the one without was male.
Q: I have some low-growing evergreens and I am wondering if there is some type of spray or granular herbicide that I can put on them to kill the grass that is growing around them? (Mayville, N.D.)
A: The grass you are seeing is very likely quackgrass. The herbicide Casoron 4G is labeled for quackgrass, and many other grassy and broadleaf weeds. Your evergreen is likely blue rug or some other prostrate cultivar of juniper. It is on the label, so it should be safe.
Q: I am looking for information on how to seed a cedar tree. I have watched birds do so on our land along our shelterbelt, and I would like to try it myself. (Academy, S.D.)
A: I am delighted to have your question as it lends credence to a recent book purchase of mine on seeds! "Cedar," unfortunately, is a common parlance given to three distinctly different genera of evergreen woody plants: "true" cedarsCedrus spp, arborvitae; Thuja spp, northern white cedar and western red cedar, depending on the species; and Juniperus spp, usually rocky mountain red cedar, which I believe is the one you are making reference to.
What you are seeing are the female "cones" or berries. Both those on the ground and on the trees can be grown. To substitute for bird digestive juices, take the pulpy berry and soak it in lye-enriched water solution for two days to soften the pulp. Then macerate the seeds and place on a screen for rinsing. The actual seeds are hard and will go undamaged for the most part. Dry the seeds completely.
Stratification of seed is necessary for 30 to 120 days at about 40 F. A vegetable crisper in the refrigerator works best for this. Plant outdoors this spring and hopefully something will come up
For my time limitations, asexual propagationtaking cuttingsis a heck of a lot easier!
Q: Does putting Christmas lights on live evergreen trees do any harm? In the past 10 years we lost two trees that were decorated every season and were wondering if it was just coincidental that they were the only two in a tree row which died. (Butte, N.D.)
A: I hope it is coincidence. The only damage I have seen is a "spiral burn" where the lights were strung and got too hot, causing the needles in those locations to turn brown. It all depends on the light intensity used. Too much for too long could cause damage.
Q: Can you tell me how to start seedlings from evergreen cones? (Rugby, N.D.)
A: Evergreen seeds are most likely all dispersed from the cones right now. The cones, pines especially, would only make a good holiday decoration at this point. Next spring, pick out the evergreen you want to collect the seed from and identify the female cones that are close to maturitywith the scales still closed. They will usually be brown at this point. Tie a bag around the cone and let it stay on until the cone scales open and drop any seeds they may contain. Plant immediately or hold in cold storage until the following spring and then plant.
Q: Can you tell me what is wrong with my evergreen trees? I was told to spray malathion for red spider mites, which I did, but they don't seem to be getting any better. Please advise me on how I can save my trees. (Carrington, N.D.)
A: Some type of environmental stressor is affecting these trees. With the information available, my guess would be either a high salt or sodium problem, a rising water table, or a fertilizer burn. Someone or something has changed—either cultural practices, construction, waste dumping, grade change or whatever—I can only guess. There is no pathogen present on what you sent.
Q: Enclosed are a few evergreen branches. I use micro acid early in the spring and later I use Miracle-Gro. The needles get brown and dry up. I do water them at times and have tried Diazanon plus. (Fredonia, N.D.)
A: Your spruce has classical symptoms of rhizophaera needle cast. All you can do is protect the newly emerged needles with a fungicide spray containing chlorothalonil (Bravo, Daconil 2787, etc.).
Apply some immediately, and twice again next spring at the end of May and June.
Q: I can't seem to find any information on the plant called Lilac-Mexican Heather, Cuphea hyssopifolia. Can you help me on this?
A: Your plant is an evergreen in zone 10 (south Florida). It prefers moist, but well-drained soil, full sun, and is killed off if the temperature goes below 32 F. It also known as False Heather.
Q. Enclosed in the box is a sample of an evergreen tree. I would like to know what is wrong with it and what, if anything, can be done for it. A big part of the tree has turned brown.
Please reply as soon as possible. Thank you.
I enjoy your column very much. It is very informative. (Esmond, N.D.)
A. Your spruce is showing mostly environmental stress—wind desiccation, possible root zone saturation, possible salt burn or a combination of all of these along with some others.
If this occurred largely over this past winter, then it is likely due to winter desiccation. The buds are healthy, so in all probability the new growth will emerge OK, and there is a chance some of the older growth will re-green if the damage is not too extensive.
Q. I very much enjoy your articles and find them very informative.
I have several evergreens that appear to be afflicted by little white cushiony spots which seem to be causing the needles to turn brown. What can you tell me about this problem? (Brookings, S.D.)
A. There are three insects similar in appearance to the one you describe: cottony cushion scale, mealybugs and wooly aphids.
All three produce waxy secretions that cover their bodies; the young, crawler stages are quite inconspicuous on the host plant.
Mealybugs and scales generally deposit their eggs in white cottony masses, many times in leaf axils. All are destructive feeders, and in addition to causing direct damage to the host plant they cause indirect damage by depositing "honeydew" excrement all over the plant. This causes a sooty mold fungus to develop, which gives the plant a dirty appearance. This in turn reduces the photosynthetic capacity of the leaves, which further weakens the plant.
After all of that, if there are only a few affected branches, prune them out. If the tree is heavily infested, use a systemic insecticide like Orthene, or any other containing acephate.
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. Help! What is happening to our majestic oak trees? Here are samples from two trees in the yard in different locations. Some branches are bare and very dead. Can you detect the problem and provide a solution?
I've gleaned a lot of helpful info from your column. Others write in about their problem (and sometimes mine) and there's the answer. I like that. Keep on enlightening all of us! Thank you.
I should mention all the evergreens are dying from Rhizosphaera needle cast. Any connection? (Fosston, Minn.)
A. Thank you for the very kind words!
I'm sorry, but I have bad news. Your majestic oaks are infected with a fungus known as Oak wilt, a degenerative, vascular pathogen, that essentially shuts down the functional vessels of the sapwood. The only course of action open to you is to turn them into firewood.
The Rhizosphaera needle cast on your evergreens is not connection to the problem with your oaks.
Q. I am sending a good leaf and a bad one hoping you can tell me about this plant and the name of it. I have had it for four years and its very big and pretty, but the leaves turn brown around the edges. I don't know if it's too much water or not enough. I give it Miracle-Gro once every two weeks. What am I doing wrong? Please let me know and give me the name of the plant.
I love to read your articles and hope you can help me. Thank you. (Linton, N.D.)
A. Your plant is the Chinese evergreen, Aglaoneura species, an easy plant to grow that likes ample water in a well-drained container.
Your problem may be that the container is no longer draining the water freely from the root system, and causing the browning, or it may be that you have the plant located too near an air conditioner vent. They like it warm, with no cold drafts.
Q.Could you please tell me what is wrong with this Iris plant?
Also, our evergreen trees have started to grow. The bud broke, but the growth is real small. The needles from old growth are brown. They were transplanted last summer. They are about four feet tall. What could be the problem with them? Do they need fertilizer, and if so, what kind? (Warwick, N.D.)
A.The iris leaves appear to have a couple of problems: a leaf spot fungus and bacterial soft rot. These problems are usually brought on by too much water and/or poor drainage. I suggest digging the remaining healthy ones and moving them to a better location, or improving the drainage dramatically.
The transplanting operation for a tree is bound to damage some roots. This, along with the plant's re-orientation in the environment is going to produce the symptoms you describe. Providing a light fertilization sometime before Aug. 1 with Miracle-Gro will help them along.
Q. Would you please send me some literature on border plants?
We have an evergreen tree which got broken off by the last ice and snow storm in April. It is about half gone; tree was about 12 feet tall. Is there any way of saving the bottom part? It has one 2-foot branch that could be a leader, but the bottom part of the tree is quite large around.
We also have a weeping birch that had a large side branch that broke off and it is still bleeding and I see lots of insects and flies on it. Is there anything that we should put on it to hopefully save this tree? Thank you. (Tolna, N.D.)
A. Enclosed is a copy of extension publication H-322, "Annual and Perennial Flower Selections for North Dakota," from which you can select low-growing or border plants. (It is available free from any county office of the NDSU Extension Service.)
The evergreen will send out a new leader from that branch. In fact, that was a method of perpetuating Christmas tree plantations when I was a teen.
There is nothing you can do to the birch at this point. The bleeding will not directly harm it, and the insects should be taken care of by the predaceous birds in the area. Just try to keep it from becoming moisture stressed this year.
Q: Why are my evergreen trees dying? We have already cut down three large ones with the same problem. I know it isn't sunburn because the problem affects the north side of the trees. What can we do? (Maddock, N.D.)
A: If you haven't been using a phenoxy-type herbicide (2,4-D, MCPP, etc.) around these trees, then it must be needle cast--Rhizosphaera kalkhoffii. When the trees are badly infected, your best bet is total removal of that tree. If the symptoms are just starting on the trees, then spray them with either Bordeaux mixture or Bravo in early June and again in early July. This usually will bring the disease under control.
Q: I just had a 4-foot-tall evergreen tree moved, and the movers took great care in marking the north face of the tree so that when it was transplanted, it once again faced the same direction. Is there any thing to this? (Forman, N.D., e-mail)
A: Certainly, the side of the tree that faces north is different than the side that faces south. It would be like you always keeping your bare back to the south, and your face to the north, when suddenly, the two sides are reversed! Do you think the two sides are ready for the reversal of these exposures? No! And the same is true for trees. They will have a much better chance of adapting to the new site if their compass orientation can be kept the same. It's something I've preached for decades, and have finally found someone who does it ... your tree mover deserves a award!
Q: I am hoping that you can help me save my 25-year-old evergreen trees. I have had to cut out several branches that were completely brown and dead. I have noticed some bluish-white waxy or sticky mixtures on the trunk and branches, and some has dripped down on the green shoots. I have also seen places where the clear sap is oozing out on the trunk and branches. Is there something I should spray them with? I had sprayed a few places with daconil, but I don't think that has helped. They are beautiful trees and I would really like to save them. (Milnor, N.D.)
A: It sounds like the symptoms of Cytospora canker. There is no spray. Prune out infected branches and dispose of them ASAP. Then try to stimulate the trees' growth with regular watering and fertilization.
Q: I have a big 35- to 38-foot-high very bluish-green pine tree that has some grass growing very close to it. It looks like quackgrass. I have tried spraying it with something I use for dandelions, but it doesn’t seem to be helping. (Eureka, S.D.)
A: Quackgrass will not be affected by herbicides that control dandelions. Using Roundup at the base of your pine tree will not hurt it, and the Roundup should control your quackgrass.
Q: This year something started to destroy my evergreen trees. There are small brown markings all the way up to the top in spots. Needles are stripped from the branches and tips of the tree broken like to mark territory. Could this possibly be a squirrel? Is there anything I can do to keep them away from my trees? (Onaka, S.D.)
A: It sure sounds like squirrel damage. Generally, their damage is only cosmetic with no permanent damage. No control is needed, as they usually stop and move on.
Q: I transplanted my Norfolk Island pine early last summer and moved it out on the deck in partial sun. It has been showing new growth all along. It got blown over several times in strong winds. Now it is back in the house and is about 5 feet tall. Where is their native home? Are they the same as the ones that grow outside in southern Florida? (E-mail reference, Brookings S.D.)
A: The Norfolk Island pine is native to the South Pacific tropical islands. And yes, I would guess they are the same ones that are growing outside in southern Florida, even though I haven't traveled there in decades. Enjoy your pine through the winter knowing that its kin came from no place that resembles the Dakotas!
Q: I am looking for some varieties of pyramidal evergreens such as the Medora, but with more blue color than it has. I want something that will stay fairly narrow and not require much pruning to keep its shape. Do you have any suggestions for the northern South Dakota region? (E-mail reference, Aberdeen, S.D.)
A: Good question. My references list the following cultivars that may meet your interests
'Blue Arrow' - narrow, conical growth, intense blue foliage.
'Blue Haven' - neat and pyramidal in form, foliage is strikingly blue in all seasons, tends to be more open than 'Blue Arrow'. Heavy cone bearer.
'Moonglow' - a dense, pyramidal conical selection, intense bluish blue-green foliage, gets 20 feet tall by 5 feet wide
'Skyrocket' - bluish-green foliage, narrowest of columnar junipers available, getting 15 feet tall and 2 feet wide at the base.
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