As trees grow and reach large heights, some tree owners concerned with safety resort to topping their trees. Topping is the reduction of tree size by pruning back many or most large, live branches (see attached photos). Unfortunately, topping trees is more damaging than beneficial. Topping trees can cause decay, weak branch attachments, and an increased likelihood of failure.
Leaves produce food for the tree. Topping removes as much as 75 percent of the leaf-bearing crown of a tree. Reducing the leaf surface area cuts off food supplies, resulting in stress. A stressed tree is more vulnerable to insect and disease infestation. Also, the large open wounds expose the wood to decay. Stressed trees lack sufficient energy to chemically defend the wounds against pathogens.
To counter this stress, the tree activates latent buds, forcing the rapid growth of multiple shoots to produce more leaves as quickly as possible (see attached photos). This response may help counter the initial stress, but this type of growth is structurally weak. These new shoots are anchored only in the outer layer of wood, making them prone to breaking in wind or under ice or snow loads. Also, loss of energy reserves in the branches reduces root growth. The irony is that while the goal was to reduce the tree’s height to make it safer, topping has resulted in a more hazardous tree.
Large old trees, such as oaks, have great environmental and economic value, so it makes sense to give them the best professional care you can. If you’re concerned about a large tree’s health or size, have a certified arborist evaluate the tree. Better yet, hire a consulting arborist. This type of arborist does not perform tree work, so they have no conflict of interest. Look here for more about consulting arborists: https://www.asca-consultants.org/.
Sadly, sometimes removal of a tree is warranted. If that’s the case, consider planting a new tree for future generations. Camelot ReLeaf is offering native canopy trees to be planted in the fall. For a price far lower than any other source, we deliver and plant a tree in the location of your choice. We also offer site visits to help you decide on the best tree for your needs, and where to plant that tree. To find out more, contact Camelot ReLeaf.