Pruning Flowering Shrubs: Techniques for Better Blooms

Understanding Bloom Timing

The key to successful pruning is knowing when your shrub sets its flower buds. This determines whether you prune in late winter or after flowering—getting it wrong can mean sacrificing an entire season of blooms.

Spring-Blooming Shrubs

Plants like lilacs, forsythia, and azaleas set flower buds the previous summer. Prune these immediately after flowering:

• Remove spent flower clusters
• Shape the plant while maintaining natural form
• Remove any dead or crossing branches
• Avoid late-season pruning that removes next year's buds

Summer-Blooming Shrubs

Hydrangeas (panicle and smooth types), butterfly bush, and rose of Sharon bloom on new growth. Prune these in late winter or early spring:

• Cut back to a framework of main branches
• Remove weak or damaged growth
• Encourage vigorous new shoots that will bear flowers

Basic Pruning Cuts

• Heading cuts: Shorten branches to encourage bushier growth
• Thinning cuts: Remove entire branches to open the plant
• Renewal pruning: Cut oldest stems to ground level to rejuvenate

Tools and Technique

Use sharp, clean tools appropriate for the branch size. Bypass pruners handle stems up to ½ inch; loppers manage larger branches. Make cuts at a 45-degree angle just above an outward-facing bud.