Fall is the best time to prune trees and shrubs.
Fall is for planting not pruning. A good time to prune most deciduous trees and shrubs is in the late winter or early spring when they are dormant. In the fall, branches and leaves store a certain amount of food materials and removing them can reduce their cold hardiness. Shrubs that bloom in the spring set their buds in the fall, so pruning should be done immediately after they bloom each year to avoid removing their flower buds. Also, it isn't necessary to apply paint or tar to tree limbs after pruning (that's another myth). Even larger cuts left by pruning will heal just fine on their own.