The summer’s windstorms and tornadoes have left behind damaged trees all across Illinois. I’ve seen everything from broken limbs to total tree failure and trees that are uprooted — called root plate failure. Fall and winter are a good time to assess your trees and determine which ones need restoration pruning.
What’s that? Restoration pruning involves the removal of damaged or broken limbs to help the tree recover and promote tree structure and architecture. Always remove all dead and diseased portions of the tree, no matter how they got there.
Some types of tree damage — such as defoliation due to strong winds, broken twigs and branches, split branch crotches and trunks, broken tree roots and root plate failures, and leaning trees — are easily seen and diagnosed. Other storm damage is more difficult to see or diagnose. This includes cracked limbs and trunks, internal cracks, and internal rot and decay, and will probably require the services of a certified professional arborist or forester.
For trees with minor crown damage, prune broken branches back to the existing intact lateral or parent branch. Branch failure is usually not fatal to a tree but can be if more than half the crown has been destroyed.
Don’t worry about applying petroleum-based pruning paint to pruning cuts. Research has shown those wound treatments may actually slow down the healing process. For larger cuts, try a water-based shellac or varnish.
In some cases, a tree may have experienced cracks or splits to the trunk or major limbs. This type of tree damage is much more serious and may require a professional’s consultation. If the crack is near the base of the limb, removing the entire limb may be the best approach. If the crack extends into the trunk, you may have to remove the tree. Cracks will not heal.
Consider removing extensively damaged trees that are missing major limbs and have more than half of the crown destroyed. Tree recovery from extensive damage may take years, and during that time, invasive and opportunistic pathogens and insects may invade the tree.
Of course, if a tree poses a safety hazard, that takes precedent over all other considerations. Again, make that decision with a professional arborist or forester.
Finally, anytime you are making a pruning cut, be sure to disinfect your pruning tools between cuts, use the correct tool, and make sure they are sharp and in good condition.
For specific recommendations on proper tree pruning and hazard tree assessment, contact your local Extension office, Illinois Department of Natural Resources district forester or consulting forester.
Miller is a horticulture professor at Joliet Junior College in Joliet, Ill., and a senior research scientist in entomology at The Morton Arboretum in Lisle, Ill. Email your tree questions to him at [email protected]. The opinions of this writer are not necessarily those of Farm Progress/Informa.