AUGUST
2008

 

 

 

By
B. Rosie Lerner
 
Purdue
Extension
Consumer Horticulturist

 

 

 

 

 

08-07-08

Question and Answer

Q. I have a 2-acre yard that is filled with Ash trees. For years, I have had the problem of small trees or limbs growing from the base of the tree. I call them "suckers." I have cut them off right to the tree base, but they keep coming back. Some of my trees have what looks like a bush surrounding it. This happens with old trees and young trees. What causes this and how can I get rid of it?

A. Indeed, those vigorous sprouts from the base of the tree (and/or the root system) are called suckers." Ornamental crabapples are among the most notorious producers of these unwanted stems, but many other trees and shrubs can be afflicted, including contorted filbert, peach, apple and dogwoods. It may just be the nature of the plant but may also be caused by injury to the trunk or roots, thus promoting latent buds to break dormancy. Repeated cutting is only a temporary solution; often the plant responds by sending up even more suckers!

There is a product called "Sucker Stopper" sold at local and online garden centers that can be applied to the cut surface after the suckers are pruned back. You may need to reapply once or twice more during the growing season. Do not apply to the rest of the foliage or buds, as injury to the plant will be likely. Be sure to read and follow ALL label information BEFORE you apply.

Q. I live in Wabash County and have a weird growth on my trees. Some of my trees are growing large balls on their limbs; they are of various sizes and some are getting as large as softballs. There are several on each branch. A couple of my trees are almost covered with these invaders. I cut a branch off the tree and sliced open the ball; it is woody in the middle, shows no visible signs of insect life and is resistant to being burned. What are these?

A. I believe you are describing what foresters refer to as "burls," often large, swollen outgrowths on the trunk or main branches of a tree. Burls are a mass of tissue that started out to be shoot tips but never elongated into a stem. They are thought to be a response to the plant being under stress, but the burl itself is plant tissue and is not particularly harmful to the tree. Some people may perceive them as unsightly, but many are highly sought by woodworkers for their beautiful grain pattern. They can occur in most any tree but seem to be more common in maple, oak, apple, spruce and redwood.

Burls are different from galls, which are a growth that forms on twigs or leaves that is also made up of plant tissue but forms in response to a specific insect or infectious disease. The shape, size and color of the gall are specific to the invader.

Q. HELP, please! "Mock Grape" is taking over my fields and succession areas. I remove as much as possible during the fall and early spring only to have the stuff grow more and more aggressively. I really don't know what it is; it just looks like a grape leaf vine. I have another vine that seems to gobble up native stuff, too. It has pretty little purple flowers in July. Any suggestions? The natives are restless and can't run! They are losing out quickly--this year, in particular, with all the rain, I guess.

A. Vines can be some of the most persistent, challenging weeds a gardener will face! Wild grape is a possibility, and there are several species. All are vigorous climbers by means of tendrils occurring opposite the leaves. There are also a few non-grape species that are somewhat look-a-likes, including bur cucumber and moonseed. Even Boston ivy and Virginia creeper are sometimes mistaken for grape because they produce a blue berry-like fruit. The vine with pretty purple flowers might be the poisonous bitter nightshade, which bears bright red berries as they ripen.

Control of vines, especially woody vines, is a challenge, and specific measures will depend on what other plants are in the area. Cutting or spraying the plants while they are still quite young will be key. If the vines are growing amongst desirable plants, chemical control will be restricted to manually painting or wicking an appropriate herbicide onto the foliage of the weedy vine, taking care to not drip onto the desirable plants. Autumn can be a very effective time to spray with a translocated herbicide such as glyphosate, since plants will be sending carbohydrates down to the roots at that time of year. Repeated cutting back of the weeds can help and will certainly help prevent the plants from going to seed and producing more of a nuisance for coming years.

 

 

Writer: B. Rosie Lerner
Editor: Olivia Maddox,