How do I prune a spirea in the spring for optimum health of plant?
Pruning Spirea in Spring
Spirea is a lovely bush. Pruning is best done in late winter/early spring before leaves appear. This also makes it much easier to see what you are doing! Old wood on flowering shrubs isn't as productive as young wood. The goal is to keep your shrub young and flowering by removing 1/3 to 1/4 of the oldest wood to the ground annually. Also, remove thin stems to allow better air circulation and light penetration. Remove suckers that are pushing out farther than you wish. Here is a one page reference for shrub care: http://web.extension.illinois.edu/cfiv/homeowners/030524.html