Key Points Pruning wet trees can spread bacteria and fungi and slowing the healing process.Wet conditions also increase safety risks for the tree trimmer and make tools less effective.Dry, cool, and ... The Mirror: Alan Titchmarsh's pruning guide for trees and shrubs - when and how to trim Alan Titchmarsh's pruning guide for trees and shrubs - when and how to trim Southern Living on MSN: How to prune an orange tree for more fruit and better health How to prune an orange tree for more fruit and better health Yahoo: Here are the best (and worst) times to prune your trees this year All fruit trees, including apple, pear, and plum, should be pruned in the spring as they can be sensitive and don't like to be pruned in the summer heat. Here are the best (and worst) times to prune your trees this year