How to Prune Spirea

Spirea Varieties

Pruning Spirea

Spirea bushes with red fall foliage and dead flowers blossoms are ready for a prune.

• Plan on pruning a spirea bush at least twice a year. Regular, scheduled trimming promotes good health and new growth. Removal of dead or excess branches allows sunlight better penetration to the interior and lower branches. Pruning also improves airflow, which is vital to the wellbeing of the spirea. Without proper airflow, fungal diseases thrive. Lastly, routine pruning solves the ugly plant problem. Overgrown spirea has tangled, messy branches and dead stems that make it less than attractive.

• Wondering when to prune spirea bushes? The best time to prune spirea is after the first flowering. For a spring-blooming cultivar, a good time will be in late spring. For a summer-blooming variety, this will be in mid-summer.

• During the spirea trim, cut the back the tips of the stems to the top of the leaf bud. Removing dead blossoms and branches may trigger a second blooming and new foliage.

• Do not wait for the bush to fill out on its own. A lot of branches and minimal foliage means it is waiting for you to give it a much-needed cutting. Remove all the limbs without greenery; don’t be shy here. This shrub can be cut back to half it’s size and will be all the better for it.

Young spring leaves on a Japanese spirea bush appear red.

• New branch growth with many cultivars is bright red and as pretty as the spring flowers. Look for these while pruning and leave them alone.

• Prune away old, mature canes to make way for new growth. Old canes may still produce foliage, but they prevent growth and block the sun from reaching the lower branches. Cut them off at the base of the plant.

• In the fall or late-winter, prune the spirea again. This trim is more aggressive than the spring-time one. Remove all dead branches, old foliage, and old blooms. Look for dead spots and places where the undergrowth is struggling. With many large shrubs, the growth and flowering are all at the top, and underneath is a mess of dead or foliage-less branches. Cut it back far to stimulate new growth.

• Shape the spirea during this rejuvenation pruning, also. Creating a professional-looking, rounded shrub is easy. Tie a rope around the middle of the spirea. Using sharp hedge shears, cut straight across the top of the bush. When the rope is removed, the bush pops back nicely rounded.

• Prune the bush throughout the year as needed. If two trims aren’t enough for your spirea, do it more often. To keep it looking good shape-wise, you’ll likely need to give it a light trim a few more times, just to keep the rounded form.

Beautiful white spirea blooming in the early spring. This plant will need a good prune after it finishes flowers.

• Spirea is an enthusiastic grower. Liberal pruning is always beneficial. Removal of dead branches keeps the plant looking tidy and attractive. You can even prune it down to ground level and it will bounce back.

• If you’ve got an older, mature spirea that looks a mess, all is not lost. Cut it back to 2-3 feet above the soil line and let it be. It will take a couple of years to regain its’ glory. However, once it returns to full vigor, it will be beautiful and more manageable. And, it will stay that way if you consistently prune it each year.

• A spirea that is in especially bad condition, tangled and unsightly, can be cut back vigorously to 6-12″ above the soil. This prompts a rejuvenation growth process. While it will take a while for the bush to regrow, it doesn’t hurt it at all.