Q. I planted an ornamental crabapple tree in my front yard a few years ago. It seems to be growing well, and it blooms beautifully in the spring. The only problem is that shoots keep growing around the base of the tree. I have been cutting them off, but they seem to grow right back. Is there anything that will get rid of these sprouts once and for all?
A. It is common for grafted trees such as flowering crabapples and cherries to develop suckers around the base. They are growing off the rootstock that the trees were grafted onto. You are right to keep them pruned off, because they compete with the top of the tree for water and nutrients. Since they are lush, vegetative growth, they are also prime sites for insect and disease problems to get started that may affect the rest of the tree. Finally, they detract from the tree’s appearance.
Unfortunately, there is no permanent solution to suckers. Never use any type of herbicide to try to get rid of them, because it can severely damage the tree itself. There is a product called Sucker Stopper, a plant growth regulator made by Monterey Lawn & Garden Products that reduces the number and frequency of re-sprouts. It is applied to suckers that are less than 10 inches tall and keeps suckers down for about three months.
You may wish to try tearing them off the tree in May while they are still small, rather than pruning them. This removes the bud that the suckers are sprouting from, while pruning leaves the bud intact. If you tear them off while they are small, the wound should be small enough to callus over quickly. By removing the bud, you are removing the source of the suckers. There are many dormant buds elsewhere on the rootstock that will continue to sprout, but that particular bud will not.
There is a product called Sucker Stopper, manufactured by Monterey Chemical Co. This is a growth regulator that can be sprayed on the cut surface of the suckers just after you cut them off. It will probably not totally eliminate the problem, but it should reduce the suckering somewhat.