Trees have a way of propagating themselves in our landscapes on their own. Many times when this happens, it is in a spot that is undesirable to the homeowner. I get a lot of questions throughout the year on how to permanently get rid of unwanted trees in the landscape. If you have trees that you would like to remove, now is actually a good time to get rid of them. I found an article from the Horticulture department at K-State Research and Extension that explains how to effectively control them. As always, you can call me if you have any questions or would like more information about how and when to control them.
Though trees are a vital part of our landscapes, there are situations where volunteer trees need to be controlled. This is often a case of the wrong plant in the wrong place. If the tree is still small and a desirable species, you may want to consider transplanting in the spring. If it is not, active control measures would be in order. Most trees resprout after cutting though some don’t. Cutting those that don’t resprout is an effective control method. For example, eastern red cedar is a very common species that will not resprout after cutting. Those that do resprout include Siberian elm, hackberry, Osage orange (hedgeball), oak, ash, aspen, cottonwood, maple, sycamore, willow and many more. These trees will either need to be dug out or the cut stump treated with herbicide after cutting. Note that when we say volunteer trees, we mean those that come from seed rather than suckers that originate from the roots of an existing tree. The recommendations given in the remainder of this article are designed to kill these volunteer trees. Using herbicides on suckers will damage and very possibly kill the original tree. Trees that commonly produce suckers include tree of heaven, honey locust, black locust, hackberry, western soapberry, cottonwood, aspen, poplar, willow and boxelder. It is also possible for larger trees of the same species to be root-grafted. Even though root-grafted trees are not suckers, they do share materials between the individual root systems and therefore herbicides used to treat one tree can be passed to its neighbor. Let’s say we have a tree we want to control that is a volunteer and there are no other trees of the same species close enough to be root-grafted that we do not wish to harm. What do we do? If the tree is any size, you probably do not want to dig it out. That leaves using a herbicide on the cut stump. Basal treatments are also possible but that is beyond the scope of this article. First decide what herbicide to use. Triclopyr and glyphosate are the herbicides most commonly available to homeowners. Triclopyr is found in many brush killers and glyphosate is found in Roundup as well as numerous other products. Read the label before purchasing to make sure that a cut stump treatment is listed. Most often the undiluted product is applied to the stump immediately after cutting. A paint brush is often used for the application though some people will dip their pruning shears in the products immediately before cutting. Regardless, it is important that the stump is treated immediately or at   likely to drip. Trees do not need to be actively growing to be controlled. Actually this time of year is a very good time to treat as long as applications are made when the temperature is above freezing
Alicia Boor is the Agriculture and Natural Resources agent for Barton County K-State Research and Extension. You can contact her by e-mail at aboor@ksu.edu or calling 620-793-1910