Spirea is a genus of woody, flowering shrubs with more than 80 species and cultivars, according to the University of Minnesota. Spirea is related to the rose and benefits from annual pruning to keep the plant branching compact and producing the maximum amount of bloom. It can also tolerate severe pruning when needed to re-size or rejuvenate the shrub.
Prune your spirea immediately after the blooms fade or in the early spring before new growth appears. Spring pruning works better for summer blooming spirea, as it will preserve more of the seasonal bloom. Spring blooming spirea will keep more of their bloom if pruned immediately after flowering.
Cut back any branches that were damaged, killed or became diseased during the winter. Place the cuts down to healthy wood or remove the branch entirely down to the crown of the plant.
Remove up to one-half of the shrub branch volume each year to encourage bushiness and new flowering branches. Follow the natural contours of the shrub as you shear the branches down to the desired length. Work evenly around the shrub as you cut to ensure a symmetrical and professional finished product.