When you can't wait to get started in the spring garden, a good task to undertake is pruning. Most trees and shrubs benefit from annual pruning. It keeps them in shape, gets rid of dead and diseased wood and encourages new growth. But not all trees and shrubs should be pruned early, especially some of the flowering ones.
Early spring bloomers set their flower buds the fall before. Pruning them early in the spring would mean losing some blossoms. Most of the time this is not what you want. However there are exceptions. It's often easier to prune when you can see the shape of the plant, before the branches are masked by leaves. Trees and shrubs that are in need of a good shaping could sacrifice a few blooms and be invigorated by a spring pruning.
There are no hard and fast rules, but here is a of list of commonly grown spring flowering trees and shrubs and the best time to prune them.
Trees and Shrubs to Prune in Late Spring/Summer, After Bloom
All flowering shrubs
Trees and Shrubs to Prune in Early Spring, While Dormant
All other shrubs
The Best Time to Prune Evergreen Shrubs
In general, prune needle-bearing evergreen shrubs in early spring, toward the end of dormancy and prior to emergence of new growth. Pruning evergreen shrubs at this time allows plenty of time for new growth to emerge, as well as plenty of time for these new shoots to harden off before the following winter. But you'll often wish to treat broadleaf evergreen shrubs (and some needle-bearing varieties) differently....
While, technically speaking, you may treat broadleaf evergreen shrubs in the manner described above, there are often reasons not to treat them as you would needle-bearing evergreen shrubs.
For instance, if they are flowering shrubs, you'll want to wait until after the flowering period to prune. Otherwise, you'll miss that year's blooms.
Moreover, for evergreen shrubs (whether broadleaf or needle-bearing) that comprise hedges, you may want to prune after their new growth has emerged in spring. It is, after all, mainly the new growth that affords opportunity for shaping (assuming, of course, that you've been maintaining the hedge all along.