When Should You Prune a Tree?

Several calls were received last week's concerning the proper time to prune a tree. The answer depends upon the species.

As a rule of thumb, ornamental trees that flower before June 1^st should be pruned immediately after flowering. These include redbuds, smoke trees, magnolias, flowering and kousa dogwoods, hawthorns, crabapples, flowering cherries, peaches, pears, and plums. Trees that flower after June 1^st should be pruned in winter or spring before new growth begins. These include golden rain trees, sourwoods, and other late-flowering trees.

Shade trees restore themselves more rapidly if they are pruned in early spring before they leaf out. The framework is bare, and you can easily see which branches need to be removed. When pruning is done in early spring, the plants are soon in full leaf and actively photosynthesizing, thus providing food and energy required for closing or sealing wounds after pruning.

Some trees, such as birch, yellowwood, elm, pine, spruce, fir, and maple, will bleed excessively if pruned in the spring. Bleeding, or loss of sap, will not harm the tree, but may be unsightly or messy around the home. Bleeding may be reduced by pruning such trees when they are in full leaf; most generally in June.