Tree experts say a basic understanding of tree biology when pruning helps promote and maintain a tree’s health and structure, in addition to improving the economic investment to the landscape. “Pruning is a science,” says Jim Skiera, ISA Executive Director. “How tree branches are pruned influences how they stand up to gravity, wind – even dangerous ice and snow storms. Too much cutback creates stress in trees. It’s important to exercise caution and a little common sense, and why it may be necessary to call in a ISA certified professional for the job.”

Why prune

Trees are most commonly pruned as a corrective or preventative measure – to remove dead branches, crowded limbs and potential hazards.

When to prune

Routine pruning can be done at any time of the year. However, the benefits are maximized if trees are pruned before the spring growth occurs.

A few things to consider before pruning a tree:

  • Always have a purpose in mind before making a cut. Each cut has the potential to change the growth of the tree.
  • Poor pruning can cause damage that lasts for the life of the tree. Learn where and how to make the cuts before picking up the pruning tools.
  • Trees do not heal the way people do. When a tree is wounded, it must grow over the damage. As a result, the wound is contained within the tree forever.
  • Small cuts do less damage to the tree than large ones.

Correcting issues when a tree is young will reduce the need for more drastic pruning later. Pruning large trees can be dangerous, It usually involves working above the ground and using power equipment, like chain saws. It’s important to consider your safety, and that of your trees. Hire a professional arborist or ISA Certified Tree Worker because they are trained in the latest safety measures and techniques. For tips on caring for trees or to find an ISA Certified Arborist® in your area, visit