Pruning Spring Bloomers
When you can't wait to get started in the spring garden, a good task to undertake is pruning trees and shrubs. Most (not all) benefit from annual pruning. It gets rids of dead and diseased wood, encourages new growth and keeps them in shape. Some trees and shrubs should not be pruned early, especially some of the flowering ones.
Early spring bloomers set their flower buds the fall before. Pruning them in early spring could mean losing some blossoms which may be why you find yourself asking "Why don’t my flowers bloom?” Most of the time this is not what you want. However there are exceptions. It is often easier to prune when you can see the shape of the tree or shrub, before the branches are masked by leaves. Trees and shrubs that are in need of a good shaping could sacrifice a few blooms to be invigorated by a spring pruning.
Here is a list of commonly grown spring flowering trees and shrubs and the best time to prune them.
Trees and Shrubs to Prune in Late Spring or Early Summer (After Bloom)
Azalea (Rhododendron species)
Beautybush (Kolkwitzia amabilis)
Bridal Wreath Spirea (Spirea x vanhouttei)
Flowering Crabapple (Malus species and cultivars)
Forsythia (forsythia x intermedia)
Hawthorn (Crataegus species and cultivars)
Hydrangea, Bigleaf (Hydrangea macrophylla)
Lilac (Syringa vulgaris)
Magnolia (Magnolia species and cultivars)
Rhododendron (Rhododendron species)
Serviceberry (Amelanchier x grandiflora)
Slender Deutzia (deutzia gracilis)
Weigela (Weigela florida)
Trees and Shrubs to Prune in Early Spring, While Dormant
You can still shape the following list of trees and shrubs, while they are still dormant during spring.
Bradford Pear (Pyrus calleryana)
Butterfly Bush (Buddleia Davidii)
Crape Myrtle (Lagerstroemia indica)
Flowering Dogwood (Cornus florida)
Flowering Plum (Prunus blireana)
Golden Rain Tree (Koelreuteria paniculata)
Honeysuckle (Lonicera fragrantissiam)
Hydrangea, Peegee (Hydrangea paniculata ‘Grandiflora’)
Potentilla (Potentilla fruticosa)
Spirea (except Bridal Wreath) (Spirea japonica))
Wisteria (Wistera species)