Tree pruning or tree trimming is best done when temperatures cool in the fall and before buds start to grow in the spring. Removal of dead, broken or damaged limbs can be done at any time. Deciduous trees, which lose their leaves every year, should be pruned in late fall through winter. To avoid Oak Wilt Disease, oaks should be pruned between November and March.
Thinning should be done throughout the tree, removing 10 to 20 percent of branches from the edge of the canopy. Large trees benefit from removing end parts of branches between 1 and 4 inches in diameter, while small ornamental and fruit trees can be thinned by removing smaller branches between ¼ and ½ inch thick. In general, after the leaves fall and before the flowers appear is the ideal window for pruning or trimming trees. Light summer pruning can be done on most deciduous trees and shrubs, while a more intense pruning should be carried out when the tree is inactive, preferably in late winter before active growth begins.
Trees such as maples (Acer) bleed heavily sap and should be pruned in winter while trees are dormant. Shrubs that bloom in spring, such as lilac and forsythia, bloom during the growth of the previous season and must be pruned within two weeks after flowering. The need for pruning trees can be reduced or eliminated by selecting the right plant for the location. Advances in plant breeding and selection in the nursery industry provide a wide variety of plants that require little or no pruning.
However, even the most suitable landscape plants often require pruning. Taking advantage of these months of inactivity gives you time to develop a plan for pruning and trimming trees in your landscaping. By pruning and trimming trees in specific ways, you can encourage fruiting and flowering, shape plants into specific shapes, and control plant size. If you are trimming the trees yourself, look for the moving services offered by the city.
Knowing when to prune trees keeps them healthy in the long run and sets them up for a robust growing season. Late winter and early spring pruning helps trees sink all of their precious energy to produce healthy new growth once the climate warms up.