In most cases, pruning trees and shrub is best done before they “wake up” from their winter dormancy and start to grow new leaves. This year’s record-breaking warm February and March meant many plants woke up earlier than usual.
If your deciduous trees and shrubs have already leafed out, delay pruning until after the leaves drop in fall. There are several reasons why it’s best to prune before a tree or shrub has leaves, including:
- You can see the branches better without leaves blocking the view.
- Reduces the risk of spreading plant diseases, such as oak wilt.
- The plant is less stressed by the removal of branches while it is dormant.
- The pruning cut heals better.
As with many rules, there are a few exceptions:
- Spring-blooming trees and shrubs, such as chokecherry and serviceberry, should be pruned immediately after the flowers have faded.
- Pine trees can be encouraged to grow slower and denser if you pinch off the spring’s new growth – a technique called “candling.”
- The “4 Ds” can be pruned any time. These are branches that are dead, damaged, diseased or defective. Note: If an oak tree requires pruning between April 1 and October 31 (to remove a damaged limb, for example), the pruning cut MUST be treated with an effective pruning paint IMMEDIATELY to seal the wound.
For pruning large, mature trees hire a certified arborist so you don’t risk the health and structure of your tree.