When to Prune the Tree
A hazardous situation may be caused by a defective branch or branches, even though the rest of the tree is sound. In this case, pruning the branch solves the problem.
- A branch is dead
- A branch of sufficient size to cause injury is cracked or decayed
- A weak branch union exists and one of the branches can be removed
- Branches form a sharp angle, twist, or bend
- A branch is lopsided or unbalanced with respect to the rest of the tree
- A broken branch is lodged in the crown. Remove the branch and prune the stub
Pruning a tree properly early in its life is a good way to effectively avoid many potential problems when the tree is older and larger. When done correctly, routine pruning of trees does not promote future defects. If done improperly, immediate problems may be removed, but cracks, decay, cankers, or poor architecture will be the ultimate result, creating future hazards. We recommend that the "natural target" pruning method be used. This pruning method is fully described in How to Prune Trees (Bedker, O’Brien & Mielke, 1995).
Remove the Tree
Before cutting a tree down, carefully consider the alternatives. The affects of removing a tree are often pronounced in landscape situations and may result in reduced property values. Tree removal should be considered as the final option and used only when the other two corrective actions will not work. Tree removal is inherently dangerous and is even more serious when homes and other targets are involved. Removal of hazardous trees is usually a job for a professional arborist. When removing your tree you should make sure the tree will be recycled so that people can enjoy the beauty for many generations to come.
Cabling and Bracing
Cabling and bracing does not repair a hazard tree, but when done correctly by a trained arborist, it can extend the time a tree [ or its parts ] are safe. Done incorrectly, it creates a more serious hazard. We do not recommend cabling or bracing as treatment for a hazard tree unless the tree has significant historic or landscape value.
Topping and Tipping - Poor Pruning Practices
Topping is the practice of pruning large upright branches at right angles to the direction of growth, sometimes used to reduce the height of the crown. Tipping is the cutting of lateral branches at right angles to the direction of growth to reduce crown width. Both of these practices are harmful and should never be used. The inevitable result of such pruning wounds is decay in the remaining stub, which then serves as a very poor support to any branches that subsequently form. Trees that are pruned in this manner are also misshapen and esthetically unappealing.
Evaluating and treating hazard trees is complicated, requiring a certain knowledge and expertise. This publication outlines some of the basic problems that may alert you to a hazardous situation. Never hesitate if you think a tree might be hazardous. If you are not sure, have it evaluated by a professional. Consult your local ISA Certified Board Certified Master Arborist. Remember that trees do not live forever. Design and follow a landscape plan that includes a cycle of maintenance and replacement. This is the best way to preserve the health of our trees and ensure a safe and enjoyable outdoor experience.