Questions on: Birch

Ron Smith, Horticulturist, NDSU Extension Service


Q: I've been looking at your Web page and you appear to be very knowledgeable about birch trees. We have a river birch that has a sticky substance on the leaves. The sticky stuff is falling on other plants and walkways. This has been going on for about three weeks. Do you have any suggestions? (e-mail reference)

A: The sticky substance you reference is either aphid or spider mite poop. Get the tree sprayed with Sevin insecticide or get a systemic, such as the product that Bayer is selling called Bayer Advanced Tree and Shrub Insecticide.


Q: I'm writing from western Massachusetts. I have a birch tree in my yard that is a couple of years old. I just noticed that quite a few leaves are stripped on the youngest branches. Upon closer inspection, I saw many little, green-striped worms crowded together on the outer leaves. I'm certain they were not there several days ago. It is disgusting! How can I get rid of them? They eat the leaves so quickly. I'm afraid the tree will be pathetic looking within a week. (e-mail reference)

A: This sounds like some type of sawfly species. By this time, they probably are gone, but left behind a damaged tree. The tree should recover and releaf for you in a week or two. I would suggest that you invest in a product called Bayer Advanced Tree and Shrub Insect Control. It will control any subsequent generations of this pest for this year and early next year. It is available at most local garden centers or national chains selling garden products.


Q: I have three birch trees in my backyard that were planted two years ago. Two of them are thriving, but the third is brown and bare at the base of the tree. My neighbor has a raspberry patch located next to this tree on the other side of our fence. Every week I have to pick raspberry weeds that have grown over to my side of the fence. Is the raspberry patch overgrowth cutting off the growth of my birch tree? The other unusual thing that happened to the birch tree is that during the first year of growth, a bunny family nested in the tree during the winter and ate some of the low growth. Could the tree be suffering as a consequence of the bunnies? (Winnipeg, Manitoba)

A: The raspberry suckers will be a recurring problem, but unless you let them take over, they will not harm the growth of your trees. As for the bunny damage, it definitely could be a factor. If the base of the tree was girdled with their feeding and nibbling, that would do it in.


Q: I live in Georgia. I have a river birch planted within 10 feet of my house. It is a healthy tree, but one of the trunks on the tree was growing too close to the house. It did some minor shingle damage and completely hung over the roof of the house. I decided to have that trunk removed. Should I cut the stump down to the ground or let it be above the ground? The other trunks are at considerable angles away from the house. Could there be an imbalance, weightwise, for the tree as a result of removing one of the trunks? What should I do to ensure the survival of the other two healthy trunks? Thank you. (Athens, Ga.)

A: Cut the stump as low to the ground as possible for aesthetic purposes. Don't worry about the tree falling over because the roots are evenly distributed and give good support. On birch trees, the roots "pancake" out more than developing deep tap roots, so you should be OK, unless a hurricane reaches that far inland! As for the remaining two trunks, I would hire an International Society of Arboriculture certified arborist to inspect and care for the tree every spring. I have a 22-year-old cut leaf weeping birch in my front yard. Every year I have a certified arborist trim out any dead wood (I'm too old to do any tree climbing anymore!) and treat for borers. A company with an arborist in your area is at http://www.treeco.biz/.


Q: I own a farm in Peterborough, Ont., which is northeast of Toronto. It was a wheat farm, but it has been dormant for 15 years. Since the land was dormant, birch trees have taken over. The trees are 20 to 25 feet tall. There are many clumps with three to four trees. Do you think that these trees could be transported and sold at nurseries using the right tree spade? I'm thinking of purchasing a tree spade to transplant these trees. (e-mail reference)

A: I would suggest finding out if there is a market for the trees and what price you could charge. You will need to set limits on the distance and time of year to move them. You also will need to determine ease of access to the properties where they are to be moved and what kind of guarantee you will provide. You should root prune the marketable trees for at least a year prior to moving them. You didn't say whether or not you've had horticulture experience or education. You need to figure what the cost and maintenance of the spade will be and how many years of service you can get out of it. In addition, you need to find out how many trees you will have to move to recoup your cost of investment and return a profit. I encourage you to do extensive homework before tackling this venture because you don't want to come out on the short end of the financial stick!


Q: I have nine clumps of river birches in my yard. This winter we had an awful ice storm that broke the tops out of four of the clumps. I had two trees taken down out of one clump. During the weeks after the trees were taken down, the stumps were almost pouring out a substance. Is this sap? It is colorless, odorless, tasteless and feels like water. (e-mail reference)

A: This is sap pressure coming from the roots. It will stop when spring arrives. If you were to have a chemical analysis made of the liquid, you would find it rich in carbohydrates, which are used in the surge of spring growth.


Q: Does all the bleeding advice you give on river birch pruning also apply to the roots of the tree? I cut a root that has wept for seven days. Should I do anything other than cover it up with dirt? (e-mail reference)

A: Yes, the advice also applies to the roots. There is nothing you can do about it and you don’t need to worry about it. I would cover the root with soil. It eventually will stop weeping as spring continues to arrive in your area of the country.


Q: I have a 9-year-old river birch in my front yard. After I pruned it this week, water started leaking out of the cut branches. I know people have mentioned leaking sap in your column, but this was not like any sap I've ever seen before. It was clear and not sticky. The sap was running out so much that I could catch it in the palm of my hand. This lasted for about 45 minutes. It has been pruned before, but I've never seen anything like this! Any suggestions on what it might be and should I be concerned about it? (e-mail reference)

A: There is a reason why we don't recommend early spring (or late winter) pruning of certain tree species. It causes unnecessary concern for folks like you. What you are seeing is indeed sap flow that is caused by the high turgor pressure in the vascular system of the tree. Elms and maples would respond the same way if pruned at this time of year. All of these "bleeders" should be pruned later in the season. Pruning should take place once the leaves have elongated and pruned only when absolutely necessary. No harm will come to the tree from this, I assure you, but expect the area under the cut branches to be a little sticky for a while!


Q: We just purchased a weeping birch at a garden show and plan on planting it in the front yard. We have three other birches in the front yard. How tall should I expect this weeping birch to get? Are there any special planting tips that you could give me? (e-mail reference)

A: Like so many people who write to me for advice, you gave me no clue as to what part of the country you live in. In most instances in a decent landscape setting, these trees will top out at 35 to 40 feet. Keep in mind how the tree spreads as it matures. The tree will do best if you can "bed" it, which means building a large mulched area around the base of the tree to keep the roots cool. You might want to consider planting some herbaceous ground cover under the canopy of the tree. Plants, such as hosta, sedum and creeping phlox, will help keep the roots cool when combined with organic mulch. Soil compaction and heat stress on the roots predispose this beautiful tree to being attacked by the bronze birch borer. I have had one growing in my front yard for the past 20 years and absolutely love it!


Q: Would you please tell me what can be done with a bare area of a birch tree? This is a healthy tree otherwise. The tree always had the bare area. Would you have any other advice about shaping, caring for or replanting? (Esmond, N.D.)

A: Birch trees should be pruned minimally. Sorry to say, but the condition your tree is in cannot be corrected by pruning. Basically, you have two choices. You can live with what you have or replace the tree.


Q: Some of the roots on my birch trees are above ground. Some roots are high enough to hit the deck of my lawnmower. They also are pushing up the bricks we have around the trees. Can I trim some of the highest roots without damaging the trees? (e-mail reference)

A: I would suggest that you contact an International Society of Arboriculture-certified arborist to do the work. Go to http://www.isa-arbor.com/findArborist/findarborist.aspx and follow the prompts to find an arborist close to your home. Be sure the contact is familiar with root pruning and check the person’s credentials. Random removal of roots without understanding the consequences of doing so could result in the tree becoming a potential hazard in high winds.


Q: I planted a lovely bare-root silver birch specimen back in April. I had small brown leaves and some new branch growth throughout the summer. Now I see little evidence of buds and the tree has become brittle when birds land on the branches. Is my tree dead or do I leave it alone? (e-mail reference)

A: If the tree branches break when birds land on them, they are dead. I would suspect that the entire tree isn't in good shape. Since it is so young, I wouldn't waste my patience on it. Try again this spring. But first, find out why the tree died. It may have been planted too deeply, overwatered or has extensive root or borer damage.


Q: I planted a small birch tree last year. It lived through the summer and looked strong. However, as the summer passed, the tree started spreading or opening up at the top. The three trunks the tree now has were not strong enough to hold the tree upright. I am guessing that the nursery did not prune the tree correctly. I also noticed that one main truck is split into two equal branches. I heard that I should cut off the main bud on the limb I want to keep as a branch. Is this true? Also, how do I get strength built up on the remaining trunks so it will stand on its own? (e-mail reference)

A: You are better off contacting the International Society of Arboriculture to find the nearest ISA-certified arborist. To find a list, go to www.isa-arbor.com/home.aspx. On the left side of the Web page, you will see "find a certified arborist." Click on that and follow the links for a list of qualified companies or individuals. Check them out to be sure they still are certified and ask for references, especially if you are going to hire someone to do pruning work. Generally, these trees are self-supporting, so your comment about the tree not being strong enough to stay upright is confusing. It leads me to think that the tree was not nursery grown. I could be wrong, so get someone to check it out for you.


Q: I have a few birch clumps that are dying on top. They could be river or paper birch trees. Last year we cut a portion of the top off on one tree in an effort to save the tree. That tree in the clump seems OK this year, but the top on the other is looking a bit thin and has smaller leaves. Any treatment you can share with me or is this the slow death of a birch tree? We did spot some holes around the girth of the tree. Is this the borer we have read so much about? (Carrington, N.D.)

A: Unfortunately, it is borers. You can attempt to save the tree by applying the Bayer product that has been promoted on the market. It is a systemic that moves through the vascular system and kills the borers as they feed. It is too late for this year, but you might be able to save the tree next year with an application. It has to be a judgment call on your part. If the damage has been too extensive, you might be better off taking the tree out.


Q: Could you please answer a few questions about a royal frost birch? Is it really more resistant to bronze birch borers and leaf wilt? I would love to plant it in my front yard. Will it survive if it is in full-sun and facing west? Also, I have read that I should plant birch in the spring and put 6 inches of mulch around it. (Crystal, Minn.)

A: It is resistant to bronze birch borers and leaf wilt. Put 2 to 3 inches of mulch around the roots, not 6 inches. It will survive if you can keep the roots moist during periods of inadequate rainfall. My 21-year-old cutleaf weeping birch is doing fine in my front yard. In fact, it is the pride of the property! Get one, take good care of it and enjoy watching it grow.


Q: I bought and transplanted a weeping birch last spring. The tree did great, but this year it appears that the top half is not producing leaves. I thought this was how it grew. I was going to trim the nongrowing limbs, but the buds and limbs appear to be alive. I am at a loss! (e-mail reference)

A: This could be evidence of the start of a bronze birch borer attack. Check the branches to see if there are any d-shaped holes or swelling under the bark. The borers can kill a birch tree a limb at a time. If the borers are present, prune the infected limbs and get someone to apply a protective insecticide.


Q: We purchased a 30-year-old home two years ago. There is a wonderful weeping birch that I assume was planted shortly after the house was built. I have noticed that there are a lot of dead branches. What can I do to ensure that we have this majestic tree with us for many years to come? (e-mail reference)

A: Get in touch with an International Society of Arboriculture-certified arborist to trim the dead branches. The tree is probably under attack by bronze birch borers, which if allowed to go unchecked, will kill the tree at some point. The tree also should receive an injection of a potent insecticide that will translocate through the transpiration stream and kill actively feeding larvae. Additionally, the tree should be fertilized almost every year and kept watered to increase its vigor. This will make the tree less attractive to the borer.


Q: I have a weeping birch tree that's about 32 years old. It has some rows of holes in the main trunk that I think are caused by a sapsucker. I don't think that they are D-shaped enough for them to be a birch borer problem. The top looks good, with no dying branches, but there are some weak or dying branches on the lower part of the tree. Sapsucker holes are typically lined up in a row. Are birch borer holes lined up in a row? (e-mail reference)

A: Those are sapsucker holes. If they were birch holes, the distinctive backward D-shaped holes would be obvious and the bark would be swollen from larvae feeding activity. Also, in 100 percent of the cases I have known that were birch borer activity, the damage is at the top of the tree on the younger, tenderer branches and thinner bark. Typically, sapsucker holes are lined up, but they also deviate a little. I have a weeping birch in my yard that has the same sapsucker markings.


Q: We have a weeping birch that was doing well. This spring, there was a large, dead branch that my husband cut off. Should the stump be sealed or tarred or is there anything else we should do? The tree has been treated for birch leaf miner. (e-mail reference)

A: There is nothing more to be done. I have an identical tree in my front yard. What killed the branch probably was bronze birch borer. Leaf miner seldom, if ever, is lethal to birch trees, but borers are. You might want to get the tree examined by an arborist to determine for sure that it was the borer that caused the death of the branch. If caught in time, treatments can be applied that will control the spread. You don't want to lose this very beautiful tree!


Q: I have a question about my paper birch. The kids next door ripped off half the bark on one side of the tree. The tree seems to be doing fine, but it is older and probably more resilient. Is there anything I can put on the exposed wood to help the tree grow back the bark? (e-mail reference)

A: Yes, tie those obnoxious kids to the tree until it heals! Just kidding of course, but the tree should be able to heal itself without anything being done to it other than keeping the kids away. Healthy trees can compartmentalize wounds better without any interference from us. Tell the kids they have attacked one of my favorite trees and I will not put up with them doing that! I have a special punishment for thoughtless people who deliberately vandalize trees.


Q: I have an ornamental weeping birch in my garden. Many of the branches are touching the ground and part of a stone patio. Should I trim those branches so they don't touch? Also, the tree doesn't seem to grow. Do you think I planted it too deeply? The tree is leafing beautifully and appears to be very healthy. (Minneapolis, Minn.)

A: Be patient because birches have a continuous growth cycle, not a start-and-stop cycle as do many other species. Now that it has leafed out, you can carefully prune the branches that are in your way. I have to do it every summer with my weeping birch, which is now close to 60 feet tall. To check on the planting depth, dig around the base of the trunk with your hands and see if you hit root flares right away. If you do, the tree is OK. If you have to go down more than 2 to 4 inches before reaching the roots, it was planted too deeply and the soil should be pulled back.


Q: I had three of my river birch trees trimmed on April 1. Now the trees are bleeding a lot of sap. I was reading on your Web site that birches should be trimmed only when the leaves are out. I thought the professional tree trimmers we hired should have known this. Will our trees die? The sap also is bleeding on some of my perennial plants. Will the sap kill the plants? At this point, what should we do to save the trees? If the trees’ health is at risk, is the tree trimmer we hired liable for damages? Before he trimmed the trees, I asked him repeatedly if it was OK to trim them at this time of year. He said the trees would be fine! He also trimmed some maple, oak and elm trees for us at the same time. I hope all our trees are OK!
(Bloomington, Minn.)

A: Your trees will be fine. The reason for the delay in pruning bleeders, such as birch and maples, is for the very reason of your concern. Unlike humans, trees will not bleed to death. From a disease standpoint, pruning while they are dormant is a better choice. I have a huge birch in my front yard. I have a professional prune it every summer with no disease consequences or sap flow. The only way your tree trimmer failed you was about not informing you of the sap flow this time of year. That is not a crime on his part, just an oversight. Relax and stop worrying.


Q: I cut a branch off a paper birch. In the spring, the tree began to drip sap. I panicked and called the local nursery. They recommended using a pruning seal. I raced to the hardware store and bought some. I sprayed on the sealer, but it immediately melted off. I called the nursery again and they suggested using a pruning tar. Again I raced to the hardware store, but the tar applied melted off as well. After several tries, I gave up. Using water and a paper towel, I tried to dab off the residue. I searched the Web and saw your question-and-answer column and decided to leave the tree alone. Now, a little over a week later, the cut has a white, lumpy mold growing on the surface. Should I do anything? (e-mail reference)

A: Shame on the nursery for telling you to attempt to stop the flow of sap! It won't work, as you discovered. The mold that is growing is a saprophyte, not a parasite. This nonthreatening fungus is feeding on the carbohydrate-rich sap coming from the cut. It will disappear with time. If it is still present in June and the tree is leafed out, go ahead and make a fresh cut to facilitate healing. The tree will not bleed at that time. I assure you the birch tree will not suffer any dire consequences from this early spring cut.


Q: I have a heritage river birch (three clumps) that I planted 12 years ago. The tree is 7 feet from my basement wall. I haven't been concerned about foundation damage until I noticed a crack in the mortar on the blocks closest to the tree. There are no other cracks in any of the basement walls. Should I be concerned that the tree may be damaging my foundation? (e-mail reference)

A: The best way to find out is to do a little digging this spring. If there is a root pushing against the foundation, cut it out, seal any cracks with water-proofing sealer and place a root barrier between the cut root and the foundation. If the root isn't there, I'd still suggest sealing the crack to prevent any moisture from getting in there and causing problems. My birch tree is about the same distance from our foundation, but I have not found any extensive root activity or any evidence of damage.


Q: I have three birch trees within about 5 feet of my house. I bought the house two years ago and I believe the trees are about the same age. They are approximately 30 feet tall. Are birch tree roots aggressive? Can I expect damage to the foundation of my house? Thanks for your time. (e-mail reference)

A: Nothing to worry about unless you have a leaky foundation, which you obviously don't or you would have noticed root damage by now. I've had a cutleaf weeping birch growing next to the foundation of my house for the past 20 years, but have not experienced any damage. Enjoy these beautiful, majestic trees.


Q: I’m thinking of taking a cutting from a birch tree instead of buying a seedling and waiting five years for the tree to turn white. Is it possible to take a cutting from a tree that is white to grow roots? I know I can try air layering, but prefer using a cutting. (e-mail reference)

A: Cuttings will root if you pay attention to detail. In other words, rooting may be a challenge for some. Take the cuttings in late summer (Sept. 1) and dip the cuttings in a rooting hormone. After that, place the cuttings under a mist. Allow the cuttings to go through a normal dormancy and then move the cuttings after their spring flush of growth. Some swear this works, but others swear it doesn't. I never have rooted any because I’ve always depended on seedling development, with the bark turning white in two to three years.


Q: I’ve been reading your columns and think they are very good. The columns made me start to think about my tree! I bought a cutleaf weeping birch at a 75 percent off sale. It looked OK when I transplanted it three weeks ago. The top branch (looks like the leader branch) had one small branch with leaves at the top. Below that are numerous branches. I put in green, light root starter and the tree is budding like crazy. But, the top bunch of leaves died and also possibly the branch. The tree has about eight leaves with scales that I am getting rid of with systemic insect killer. I read that such problems are caused by bronze birch borers, but not if the tree is less than a year old. What do you think is the reason for the top dying off? (e-mail reference)

A: Good moves on your part! I think the tree will be OK. Everyone told me I was crazy to plant one 20 years ago. Now it is the most dominant part of our property and looks beautiful. Keep it watered and the turfgrass away from it!


Q: My mother-in-law who is 88 loves trees and has a lovely cutleaf birch. Is there a difference between a cutleaf and a cutleaf weeping birch? She says hers is just a cutleaf. She also is wondering if there is any way you can start a new tree from seed. Thanks for you help! (Wolford, N.D.)

A: There are cutleaf weeping birch trees and semi-weeping birch that have the cutleaf foliage.Birches can be started from seed, but the character is liable to be lost. Normally, nurseries will graft these beautiful plants because the cutting success is only 25 percent or less with great effort.


Q: I had a gorgeous silver birch in my front yard. I was getting very sick and discovered that I was allergic to the tree. To my regret, we had it cut down and the stump ground down. My problem is that there are millions of baby birch trees coming up in my yard. How can I get rid of them? I continue to get very sick. Even walking on my lawn and stepping on them give me a severe allergic reaction. I hope and pray that you can help me get rid of the baby trees and give me relief from my allergies. Any ideas are welcome. (e-mail reference)

A: Get a professional lawn care operator to apply broadleaf herbicide to your lawn to control the “weeds” that you have, which in this case are the sucker growths coming from the roots. Probably a material such as Trimec should be used, as it will translocate into the roots. Sorry to hear of this unusual allergy!


Q: We recently planted a weeping birch in our front yard. It’s been in the ground for more than two months and was doing very well until a couple of weeks ago. I noticed that some of the leaves were turning yellow. I watered the tree thoroughly. We returned home after the long weekend to notice that there were more yellow leaves than when we left. I think I may have overwatered the tree. There has been very little rainfall in our immediate area, so I thought it could do with a couple of real good waterings. Do you think I’ve overdone it? If so, what should I do to help it along? It’s a beautiful young tree and we don’t want to lose it. (e-mail reference)

A: I’m willing to bet that you have the tree planted too deeply. The crown (where the stem meets the rootball mass) should be at ground level, not lower. As little as 6 inches deeper can cause what you describe. Heavy watering only exacerbates the problem. Pull some of the soil from the rootball back to the surrounding soil level. If this is not the problem, then I am at a loss to help you.


Q: I have a paper birch with three main trunks. Last year everything was fine. This year it looks as if two of the trunks area dead. One trunk does have a new shoot on it. Most of the branches break off. What is going on? The third trunk seems fine. (e-mail reference)

A: Sounds like bronze birch borers have moved in and destroyed the tree. Look for d-shaped exit holes about the size of pencil lead in the branches and trunk. It is just a matter of time before they move to the remaining trunk.


Q: I hope you can answer a question for me. Last fall we bought a new home (the birches sold us). A dump truck broke off a medium-sized branch about 10 feet from the trunk. It is now spring and the tree is leaking sap. It has no smell and is not sticky. How can I save this wonderful tree? (e-mail reference)

A: Make a clean cut, with loppers or a saw, back to the trunk or a lateral branch. The sap flow will not hurt the tree and will stop.


Q: Last fall, the deer raked the bark from our clump birch tree. Since it had a south exposure, I wrapped it for the winter and have just taken the wrap off. One limb has a very deep wound that goes deeper than the first layer of the bark. It is now weeping and covered with insects. What should we do to help the healing? Will it be OK to leave it open and hope for the best with time or does it need some paint/tar or something else to protect it from the elements? We also have pruned a few apple trees. The branches were more than an inch in diameter. Do they need something on them or will they heal by themselves? (Verona, N.D.)

A: In both instances, the trees are best left to heal on their own. The sap flow will not hurt the tree. The insects will be food for insect-eating birds, such as woodpeckers and sapsuckers. Research shows that trees will heal better without any protective covering if they are otherwise healthy. If they are not healthy, a covering will not help.


Q: We moved into a new home and are ready to plant trees. Our septic system is in the back yard. What tree will do well within 20 feet or less of the drainfield? I was planning on a clump birch. If that tree works, can I buy it bare-root? (Davenport, N.D.)

A: Plant the birch because it is about the most innocuous tree you can plant near a septic system. I never have seen a bare-root clump birch available. I doubt they are.


Q: We built a home in a new development that used to be farmland. I have a three-clump birch tree that my husband planted in September 2003. In the spring of 2004, one of the trunks did not leaf. The branches were dry and brittle. The other trunks had leaves, but not many. Is there something that can be done to help the dead-looking trunk? If not, what do you recommend to save the remaining trunks? One tree farmer told us the soil here has too much clay to grow birch trees. Others have told us the opposite. Does a container-grown transplanted tree take more than a year to adapt to a new site? Any recommendations are appreciated. We have a sprinkler system that sits on an elevated area and slopes away from our home and foundation. Does it make a difference? (e-mail reference)

A: Birch can grow in clay soils, as long as the soil is not compacted or kept too wet. I suggest replacing the tree. This time, dig a wide hole and don’t plant the tree any deeper than where the roots and stem meet. Planting too deep and then overwatering are common problems. Mulch the area with bark mulch at least 2 to 3 feet out. Monitor your irrigation system so you are not watering your lawn more than is needed. Most grasses can get along on 80 percent of the evaporation-transpiration rate. This is data available from your local weather station or Extension Service. Most people overwater their turfgrass by more than 30 percent to 40 percent.


Q: How and when should a birch tree be trimmed? (e-mail reference)

A: Birch trees should be trimmed as little as possible and only when absolutely necessary (when there are dead or broken branches). You may want to trim after the leaves have fully expanded to cut down on excessive sap flow.


Q: I have a birch tree that woodpeckers are pecking full of holes. What can I do to stop them and how do I repair the tree? Also, I have a silver maple on the west side of my house that has stopped growing the last three years. It is 25 feet from two other maples planted at the same time. The other two are doing fine. All are about 25 feet from the house. The problem tree outgrew the others for the first four to five years. It will green up but the only new growth is on the lower part of the tree and is minimal. Its leaves are only half the size of the other trees’ leaves. I tried foliar feeding with Miracle-Gro a few times last summer, but it did not seem to help. (E-mail reference)

A: You will have to draw on your creativity to control the woodpeckers. Some people get good control with Tanglefoot, aluminum foil, or a stuffed owl or falcon in the tree. Woodpeckers are very intelligent birds and not easily fooled, so you will have to draw on a mixed bag of tricks. I suspect a root rot problem with your silver maple. You might want to call in an International Society of Arboriculture certified arborist to see if there is any remedial action you can take to save the tree.


Q: I have a white birch tree that is rotting and splitting at the base. Is there anyway to save the tree? (E-mail reference)

A: Where there is rotting, it is unlikely that you will be able to save it. You should consider removing it before it poses a personal or property hazard. If there were no rot, you could drill through the tree using a drill bit 1/8 to 1/16th inch larger than the threaded rod you would place through the trunk. Secure the rod using a round washer and nut, with the washer counter-sunk to the cambial area. If rot is present, like you think it is, then use a second washer, placing it on top of the secured nut, and securing the second washer in place with another nut. Wood will grow around and between the washers and strengthen its holding power. You might want to consider using two rods to brace the trunk. The first and most crucial one is inserted just below the crotch, while the second one is inserted about a foot higher.


Q: We have a paper white birch that looks like it is dying. It is about 20 years old or more. The top half didn't develop leaves. The bottom half has leaves and looks healthy. Is there something we can do? By the way, we planted three trees to make it a clump birch. (Milnor, N.D.)

A: The birch is very likely suffering from bronze borer attack. I doubt that you can save it at this point. Once that pest gets started, it is just a question of time before the tree is completely destroyed and yours is about the right age for this to happen. Sorry!


Q: I have a weeping birch that is about 17 years old and 50 to 60 feet tall. It’s a very nice tree and we enjoy it very much. This spring it leafed out very nicely but about a week ago I noticed that, about 10 feet from the top, the leaves had turned brown and were dying. What happened? I hope it doesn't continue down the tree. Anything I can or should do? (Carrington N.D.)

A: The same thing that is happening to my 18-year-old weeping birch. You have bronze birch borer damage. About the only thing you can do is hire an arborist to come out and trim it back to fresh wood. If licensed, have the arborist inject some insecticide into the trunk and hope that you got to it in time. I hope I can milk a few more years out of mine. The one arborist in Fargo that was servicing the tree is now out of business or moved. I hate the thought of losing this beautiful tree but it was worth enjoying it over the years that it thrived.


Q: I live on a farm near in the central part of South Dakota. We would like to plant a tree in the front of our home which would have three or four trunks and white bark. We are looking at something on the order of an aspen or birch and hopefully a tree that won’t grow higher than 30 feet at maturity. Your recommendation for specific species/varieties would be appreciated. (Highmore, S.D.)

A: You are aiming directly for a white clump birch, but I would encourage you to consider a river birch, clump form, instead. The cinnamon-colored bark is very attractive and the tree is far more adaptable to our Dakota prairie environment and will live a lot longer. If you can, try and get the cultivar known as heritage. It is a tree to equal or beat out the best. In fact, if there was a champion of Champions, this tree would be it. It tolerates 40 below cold and can stand heat found in three zones south of you! Even if you have to go out of state to get it, do so.


Q: I just had a flowering pear and a white birch tree planted last week. The leaves appear to be dying on both. Am I watering them too much? I was told to water them everyday for a while. Are the leaves supposed to fall off the white birch in the fall? I also have two purple leaf plums that have leaves that look sick. Do they fall off in the fall and bloom white flowers? Could you please help me as I don't want to loose these trees. They were quite expensive. (E-mail reference)

A: You can relax. Both species of trees are supposed to lose their leaves at this time of year. While you do not need to water them every day, don't let them enter the winter months with dry soil.


Q: I've been having problems with plants in my yard. I have a weeping birch tree. Most of the leaves on the tree are yellow, then they curl up and turn brown, along with a mountain ash and a plum tree, I've had branches on the trees that die from this. I also have annual bedding plants that are doing the same. They are a nice dark green when I transplant them, and about a month ago they started to turn yellow and die. I sent a soil sample away, and the report said I needed more nitrogen. I've been fertilizing with a liquid fertilizer 30-10-10, about once a week. It seems to be holding the tree leaves from turning brown; some annual plants are at a standstill but still yellow. I've also tried spraying iron on the leaves, but nothing seems to be working. Do you have any solutions to my problems. (E-mail reference)

A: It sounds like you have a problem beyond nutrition. The soil may have been contaminated with a sterilant or pesticide that is causing the problems. It is unusual for such a wide species range to be affected this way without it being a soil problem of this sort.


Q: We have two clump white birch, one of which is 15 years old and is a beautiful tree.

Very early this spring, the first part of April, it had buds on it, but now since the frost the middle to end of May it appears dead -- no green leaves, branches brittle, etc. A younger tree next to it is in the same shape. The really puzzling thing is a third clump birch -- the youngest of all -- is doing beautifully. My husband did put 10-10-10 fertilizer on all three trees the first part of May before that killing frost. Could that be the culprit? We are able to find green bark on the two bad looking birches but only on the main trunk. We also have a 4-year-old cottonwood that has leafed out but rather than green leaves they are yellow green similar to what you see in the fall when the tree is dying off. We have been TLC'ing the trees (frequent generous watering) but are wondering, should we be pulling them out and replanting with something else, or just be patient and maybe they will pull through? We're just sick about the birch as we have really nurtured them and they were just getting to be such handsome trees. (Wishek, N.D.)

A: Hold on for a few more weeks. If the tree has not re-leafed by the Fourth of July, then it is likely a goner, and the fertilizer your husband applied is not at fault. Borers sometimes get to these beautiful trees and kill them off when we are appreciating them the most. The cottonwood doesn't sound much better. I don't know what to tell you the problem is as it could be too many to consider. Most likely something is going on with the root system.


Q: Now that the leaves are off the birch trees in my front yard, I see that they have never been trimmed. I actually thought they were a sort of cross between a birch and a willow.

Should I also wait until to trim them? (Fargo, N.D.)

A: Birch trees should be pruned very little if at all. There are a couple of reasons for this:

Birches have excessive sap flow from pruning wounds. While it is not directly harmful to the tree, the sap is a rich source of carbohydrate that is attractive to insects in the spring. Consequently, any trimming that is necessary (dead twigs or branches creating a hazardous situation, etc.) should be done in the late spring, mid June when the tree has fully leafed out and the sap flow has slowed somewhat. The bronze birch borer is in our area and loves to prey on white bark birches, especially those under stress from not enough water, soil compaction, wind breakage or severe pruning. Believe it or not, the borer has the ability to detect trees that are stressed and will lay eggs on the upper part of the tree, causing dieback to take place from the top down. The adult is a bronze beetle, and the larvae or grub is small and white, and mines in irregular galleries just under the bark. The younger trees are usually not attacked, as ample moisture and nutrients are readily available. But as the tree gets about 15 to 20 years old the stresses of age usually attract this pest and off to work he goes. Once visible symptoms of borer damage are evident, the tree usually dies out within three to five years or becomes so misshapen that it is no longer a landscape asset and removal is necessary.


Q: We recently moved into a farmstead south of Fullerton, N.D. in Dickey County. I would like to plant some shade trees in the yard. I have seen a tree in the Wahpeton Chahinkapa park and also in Ellendale. It has white and black bark like a birch, the branches hang like a weeping willow, but the leaves look like a maple. Any idea what this is and where I might purchase one? Are they hardy and worth planting? (Fullerton, N.D.)

A: Your simple question got my grey matter going, but the only thing I can think of it possibly being is the cutleaf weeping birch. It at least has two of the characteristics you are talking about, and if one stretches the imagination a little, you could say the leaf resembles that of some maples. Check that out at the local nurseries and see if it fits your description. Given normal TLC, you should get 20 or more years out of this beautiful tree.


Q: My neighbor has a birch tree that is wrecking my roof. I have talked to him but he refuses to do anything about it. Can you suggest a way that I could kill this tree? (E-mail reference)

A: Absolutely not, especially for the reason given. I strongly suggest that you and your neighbor work out your differences, with you tactfully pointing out the damage the tree is causing to your roof and asking that he hire a professional arborist to come in and do some selective pruning. If he still refuses to cooperate, then I suggest legal action (you contacting a lawyer) be taken.


Q: In the past year our birch has started to produce large amounts of seeds or catkins. Is the production of these seeds a reflection of age, or does it have to do with the sex of the tree? Our neighbor has the same type of tree except it is considerable younger and does not produce any seed. Our tree is a healthy 26 years and has started to produce lots of seed. (E-mail reference)

A: That's a sign of a mature, healthy tree -- so celebrate! In some instances, overproduction of the fruiting bodies ( the catkins) is a sign of stress, or imminent demise of the tree from borers, girdling roots, drought stress, etc. But in this case your description does not reflect that, so whatever you have been doing these past two dozen years, keep it up. You apparently are doing the right thing as far as the birch is concerned.


Q: I have two huge "weeping birch" trees in my yard, which I’ve had for over 30 years. Each year these pods form on the trees and these brown particles, from the pods, are everywhere. I sweep up gallons of this mess. Is there anything or any way to stop these pods from forming, and how damaging are the particles to the soil in my yard? (Regent, N.D.)

A: Be thankful you have such healthy birches! The "pods" are male catkins which are necessary for fertilization of the female (pistillate) flowers. I assure you they are causing no harm to anything on your property and will eventually decompose on their own. Spend your time doing something that you enjoy and don’t worry about your trees. They are fine!


Q: I just planted a birch clump in my front yard. The root ball of the tree was just wrapped in burlap. I noticed when it was planted that there was not much of a root system in the burlap. The tree just doesn't seem to be doing well. The leaves have not grown any larger. The only new thing new with the tree lately is that the catkins, which were very small and skinny, have now plumped up. I am hoping that this is a good sign, as there are a few branches that are completely dead. Also, can I safely cut off the dead branches or should I wait until fall? Could the tree be planted too deep? I have watered with transplant fertilizer every other week. (E-mail reference)

A: I hope the tree was dormant when you obtained it and planted it. Bare root birch trees are generally not a good choice. Better to obtain a container grown specimen. You can go ahead and prune out the dead branches at this time. You do not need to add fertilizer as often as you are doing. If the tree is going to survive, it will do so on the soil's nutrient content and water (which is more important to the tree now). Birch have a shallow, but spreading root system. I am afraid that the nursery may have cut off too much root for convenience in handling to do the tree any good.


Q: I have a spot in my yard where I am looking to plant an ornamental tree. I have it narrowed down to either a Robinson crabapple tree or a birch. I know these are two entirely different trees, but both have things I like about them. I like the crabapple for the color of the leaves and small fruit, and the birch for the bark. I live on 3 acres and have an area coming up to the house where one of these would go. It is next to a brick walkway/flower bed. (Glyndon, Minn.)

A: You are better off with the birch. The crabapple fruit would drop on the walk and cause some problems, plus they would attract birds that can be messy on sidewalks.


Q: We have a weeping birch that the deer broke a small branch off of. The larger branch it was connected to has now dried up almost completely. I am wondering if I can cut it off without losing any more of the tree. This tree is 22 years old and very tall. I am afraid it might all die if I cut any branches off of it. Is there a way to do this without damaging any more of the tree? (Tappen, N.D.)

A: Simply cut back to where another branch exists for best healing. The wound will heal quickly at this time of year. Do not apply any dressings.


Q: We are planting a clump of three birch trees. How do we space these when we plant them to form a nice clump without overcrowding each other? Do they lean as they grow normally or do we have to lean them as well when planting them? I believe they are paper birch because we want the white bark. We do have a spot picked out with no overhead wires, about 30 feet from the house and on the east side. They will be about 15 feet from the road. (E-mail reference, Eastham, Mass.)

A: Don't worry about overcrowding them. Just work them together to the best of your ability, and plant them with no more than about an inch of soil over the roots. They will do much better if you plant them in a bed, or at least plant a herbaceous ground cover at least 18 inches around them. Do not let turfgrass encroach, or simply plant them into the middle of a lawn. The turfgrass has an inhibitory effect on the growth of trees. Keep the trees moist, not soggy. What happens is the trees will naturally root and stem graft together, making the "clump." Even though you are in a high rainfall area of the country, monitor the soil moisture, as these species do not like extended periods of drought. If you go more than two weeks without rain, water them well, no matter how old they get to be.


Q: If I cut a limb off of a birch tree, do I need to do anything with the stub that I have on my tree? (E-mail reference, Barnesville, Minn.)

A: When you cut the birch tree branch back, expect to see quite a bit of sap flow. This will not hurt the tree in any way, so don't worry about it. The later you can wait to cut it back, the less it will "bleed" and will possibly be less messy. There is no need to apply a wound dressing; in fact, doing so will only slow the healing of the cut. Be sure to cut back to just outside the "collar" (about 1/4 inch) where the branch comes off the trunk. You don't want to leave a "stub," nor do you want to cut back into the trunk.


Q: I have two huge weeping birch trees in my yard, and each year they give off pods of brown material. These seeds, or whatever, get into flower beds and everything in our yard. It seems they also stop growth of some plants or hurt the soil. Can anything be done to stop these pods from forming? These trees are about 30 years old. (Regent, N.D.)

A: These are catkins for the birch tree--or seed. The problems they cause (messiness mostly) are a small price to pay for the beauty of these magnificent trees! You are fortunate to have them around for so long. Sorry, but I know of nothing that will prevent them from forming these catkins.


Q: We are having a problem with woodpeckers making many holes in our two clumps of white birch trees. Can you tell me how to get them to stop before they kill the trees? (Hatton, N.D. e-mail)

A: I need at least a city and state for your question to be used in the column.

What your birch tree is likely being pecked at by is a sapsucker. Woodpeckers tend to make one large hole, whereas sapsuckers make rows of holes.

Now, so that you are not alone, they have been attacking my weeping birch for years, and the tree is now 14 years old. I at first worried about the damage being done, and attempted to control their activity by smearing tanglefoot (a sticky substance) near their active points. They simply moved to another spot on the tree. Consequently, I have since given up, and the tree seems to be OK. The holes they make early in the season do bleed, but by mid- to late-June, they seal up with new growth.

I know the tanglefoot works with woodpeckers, as they pretty much come back to the same spot, but I don't know what would spook the sapsuckers. You likely have nothing to worry about, if their behavior is similar to the ones that work on my birch.


Q: What is wrong with my birch trees in my yard? As soon as they leafed out this spring the leaves curled. When I unwrapped the leaves I saw little bugs in each curled leaf. I'm sending along a sample. Please advise me what I can spray on my trees to save them. They also have small dead branches throughout the tree and small ripples under the bark a few places on the trunk and limbs. What is this? (Perham, Minn.)

A: There are a few things wrong with your birch tree that have nothing to do with the bugs you enclosed.

The most disturbing thing is the herbicide damage. Apparently someone sprayed a 2-4,D type of herbicide (like Trimec) over the root system to kill dandelions and other broadleafed weeds to such an extent that the material was taken in by the tree. The curled leaves and petioles are a direct result of this herbicide use.

Secondly, the bumps under the bark are likely borer tunnels. Birches are susceptible to attack by Bronze Birch Borers when they are stressed. It now becomes a question of what will kill the tree first—the herbicide uptake or borer activity? 

At this stage, there is little you can do except to see if the tree is able to pull out of this with a little help on your part. Keep it watered and fertilized, and prune out the dead branches.

I wish I could give you better news. Birches are among my favorite trees!


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: We have a cutleaf birch which is about 11 years old. The problem is that we have woodpeckers that have been putting holes in our tree, and we are afraid that they will kill our tree with all the holes. What can we spray on the tree or what can we do to deter these birds from pecking on our tree? (Oslo, Minn.)

A: I too have a cutleaf weeping birch that the woodpeckers did some work on, and it is still going strong after 15 years! If you can catch them in the act, spray the birds with a garden hose. Hang aluminum pie tins. Or apply tangle foot to the area, and wrap it in aluminum foil. Those are all the tricks I know of to discourage them. Woodpeckers often move on before their damage becomes extensive. It is illegal to shoot these birds.


Q: In 1996 I planted a cut leaf weeping birch. It grew into a straight, lovely tree. This year, the leaves gradually dried up and now the tree looks dead. Can fire blight hit birches? Can you tell me what is wrong with it and if it can be saved? (Aneta, N.D.)

A: I too, have a cutleaf weeping birch in my yard -- going on 15 years now. To me, they are one of the most beautiful trees nature produces! Concerning the apparent demise of yours, have you checked the buds or twigs to see if they are plump and green? If they are, chances are the tree will re-leaf next spring. If not, then it is firewood -- likely a victim of a root-rot fungus.


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