Early-blooming spirea shrubs that bloom in late spring and into June are best pruned shortly after flowering ends. Later-blooming spirea shrubs with flowers from June into the late summer months should be pruned during the dormant season from winter to early spring.
Spirea is a flowering deciduous shrub. The variety of spirea determines when it blooms. Pruning promotes growth, controls the size of the shrub and allows the gardener to shape the spirea as desired. Spirea shrubs with broken, damaged or diseased branches should be pruned immediately, even if the shrub is flowering or in an active growth period. Only the damaged or diseased section is cut out in these situations.