If a quick burst of growth is desired during the spring, trees should be pruned in late winter. To slow growth, trees should be trimmed in the summer. Most people trim their trees during the winter, but this should only be done after the coldest weather of the season has passed, and trees should never be pruned during the fall.
Pruning trees during the summer months allows homeowners to examine the branches carefully while they are full of leaves. This makes it easy to see defective branches or those that hang too low when they have all their leaves.
Flowering trees can also be pruned. Trees that flower in the spring should be trimmed when the flowers fade, and summer-blooming trees can be pruned in the winter or early spring.