Full Question: I have removed six Silver Maple trees (12″ – 16″ diameter) from my yard because of root intrusion and roots surfacing. Can I treat the stumps by drilling and applying copper sulfate and not be concerned with the existing roots “leaching” to newly planted trees? If there is leaching from the existing roots, how long a period must I wait before replanting a better species of tree(s)? My plans are to replant from approx. 5-6′ from the stump location of the trees that were removed.
Answer: The best treatment for stump and roots left behind from removals is grinding and time. Treating with chemicals is typically not a good solution, nor does it really speed up the process. In fact, copper sulfate is a very caustic chemical. It can cause illness and injury if inhaled or if it comes in contact with your skin. Also do not use copper sulfate if your tree stump is near a water source or if you have children or domestic animals that may accidentally come into contact with the treated area. The copper sulfate that comes into contact with the surrounding landscape can also kill grass, plants and other trees. So caution should be used if you feel the need to use it. However, grinding the stumps and planting into good soil outside the area of the woody debris from the stump is the best course of action. The roots should not cause any issues except depressions in the lawn as they decompose.
Lindsey Purcell, Urban Forestry Specialist
Department of Forestry and Natural Resources