Kathleen Cue, Nebraska Extension Horticulture Educator
Ice by itself doesn’t damage trees, but the accumulation of ice on branches creates loads that can and do result in branch breakage and complete tree failure. Case in point is the recent ice storm, creating ice coatings of ¼ to ½ inch over most tree branches. This is a tremendous amount of weight to add to trees and while structurally trees develop to handle wind and snow loads, extreme events like ice accumulation and derechos really throw a wrench into tree structural stability.
When it comes to clean-up after a storm event, “hangers”, those limbs that are broken but remain partially connected to the tree, should be removed first, especially if the hangers threaten roofs or people who may be passing below. The ideal time to prune is in April, May or June, when small reaction zones within trees makes for timely wound closure. If a storm damaged tree has sentimental value or is an important part of the landscape, hangers can be removed now but ask your arborist about completing the finished cuts and final pruning in April, May or June to promote the tree’s timely wound closure from pruning cuts. Skip any products that tout wound protection when applied to pruning cuts. These aren’t effective and actually benefit decay microorganisms.
Much of the ice damage was particularly hard on branches and trunks with included bark. Included bark is the condition where bark gets pinched between two competing limbs or stems that are close together, creating an environment ideal for decay to develop and weakening branch attachment.
Be aware that the pruning practice of lions tailing contributes to tree failure. Lion’s tail pruning concentrates the tree canopy to the ends of branches. Snow and ice loads accumulated at the ends of branches will have greater leverage to surpass the tree’s structural capabilities and branches will break.
To ask questions about your trees, you can contact me, Kathleen Cue, at the Dodge County Extension Office at 402.727.2775.
Visit the Dodge County Horticulture Web Page for more articles and information from Kathleen.
Photo: Ice Damaged Tree