Prune them heavily in early Spring, even back to about 10 inches from the soil. Once they have begun blooming, you can cut flowers for arranging and take about 5 leaf groups with each stem, which will help keep your shrubs short and compact. If they get too tall through the year, then you can prune them back to probably 24-30 inches tall and allow them to grow back. They are fast growers and will rebound quickly.

Tha