Trees that receive appropriate pruning when they’re young require little corrective pruning when they mature. However, it’s important to remember that pruning a newly planted tree should be limited to corrective pruning methods—trees need their leaves and shoot tips to provide food and the substances that stimulate new root production. Also, unpruned trees establish faster with stronger root systems than trees pruned at the time of planting.
“Being too aggressive with pruning can actually make trees grow faster and end up costing you more in additional pruning sessions,” explains Louie Carignan, owner of Bay Area Tree Co. Inc. in San Mateo. “It seems strange, but by cutting a little less, you can often encourage slower growth, which gives you more time between prunings.”
Keep these principles in mind before pruning a young tree:
• Each cut has the potential to change the growth of the tree. Always have a purpose in mind before making a cut.
• Poor pruning can cause damage that lasts for the life of the tree, so proper technique is essential. Learn where and how to make the cuts before proceeding.
• Trees don’t heal the way people do. When a tree is wounded, it must grow over and compartmentalize the wound. As a result, the wound is contained within the tree forever.
• Small cuts do less damage than large cuts. For that reason, proper pruning (training) of young trees is critical. Waiting to prune a tree until it’s mature can create the need for large cuts that the tree can’t easily close.
Making the Cut
Where you make a pruning cut is critical to the tree’s response in growth and wound closure. Make pruning cuts just outside the branch collar (the base of the branch)—it contains trunk or parent branch tissues, so the tree will be damaged unnecessarily if you remove or damage it. In fact, if the cut is large and improper, the tree may suffer permanent internal decay.
If a permanent branch is to be shortened, cut it back to a lateral branch or bud. Internodal cuts (cuts made between buds or branches) may lead to stem decay, sprout production and misdirected growth.
Pruning Tools
For small trees, most cuts can be made with hand pruning shears (secateurs). The scissor-type (bypass blade) hand pruners are preferred over the anvil-type, because they make cleaner, more accurate cuts. Cuts larger than one-half inch in diameter should be made with lopping shears or a pruning saw—never use hedge shears to prune a tree. Whatever tool you use, make sure it’s kept clean and sharp.
Wound Dressings
Wound dressings were once thought to accelerate wound closure, protect against insects and diseases, and reduce decay. However, research has shown that dressings don’t reduce decay or speed closure and rarely prevent insect or disease infestations. Most experts recommend against using wound dressings. If a dressing must be used for cosmetic purposes, apply a thin coating of a material that’s nontoxic to the plant.
