Because andromeda (Pieris) is a spring-flowering plant, the best time to prune is usually right after it has finished flowering. This gives the plant time to put on new growth and set its buds in the fall for the following spring.  If you are not concerned about flowering, you can of course also prune it in the fall. Fall-pruned andromeda will still produce flowers, but fewer of them because most of the buds have been cut off. However, the following year everything will be back to normal.

You need to decide which time of the year works best for your particular plant. Sometimes andromeda gets so big or leggy that fall pruning is best because the plant needs pruning more desperately than flowers.

Summer pruning is not a good idea because hot-weather pruning stresses the plant unnecessarily.

For more detailed information on pruning, see Purdue Cooperative Extension's Pruning Ornamental Trees and Shrubs.

For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service