My Japanese spireas are straggly in appearance. How should I prune them?

FAQ
Question: 

My Japanese spireas are straggly in appearance. How should I prune them?

Answer: 

Japanese spireas (Spiraea japonica) are small shrubs that grow 2 to 3 feet tall.  Plants produce clusters of small pink flowers in summer.  Numerous cultivars are available.  The best way to renew or rejuvenate straggly Japanese spireas is to prune them back to within 3 to 4 inches of the ground in late winter/early spring (March or early April in Iowa).  The shrubs will grow back and quickly develop into attractive plants.  For best performance, Japanese spireas should be rejuvenated every 2 to 3 years.