Spirea (spiraea) is a genus with about 80 to 100 species in the family Rosacea. This deciduous shrub is native to North America and Asia. Spirea shrubs can range in height from 2 to 3 feet tall up to 10 feet tall and wide. There are spring blooming Spirea, as well as summer blooming Spirea. All Spirea shrubs produce flowers on new wood, so cutting back this plant is an important maintenance task.
Pruning this shrub encourages flower growth, helps manage overgrowth, and aids in strong branch development. Pruning Spirea can range from trimming spent blooms all the way to cutting the plant down to the ground.
When to Prune Spirea
Spirea shrubs are vigorous growers and should be pruned at least two times a year. Regular pruning promotes new growth and good health in the plant. A good trim in the spring and again after blooming are the best times to remember to take care of your shrub. Spirea responds well to light pruning, so additional cuttings can be done anytime throughout the growing season to shape the plant.
In the fall or winter, a more aggressive prune can be done to remove dead branches and foliage, as well as spent blooms. An aged Spirea that has become unsightly and overgrown can be cut back 2 to 3 feet from the soil line. This hardy plant will bounce back even better than before.
How to Prune Spirea?
The method of trimming your Spirea bush depends on what time of year you are completing it and whether it is a trim, snipping off spent blooms, or a hard prune.
Spring - Trim after the first set of blooms are spent.
After the first flush of flowers, use clean shears to cut the tip back to the top most leaf on each stem. This removes the spent bloom and encourages new flowering.
Summer - Prune to shape the plant.
Anytime throughout the summer, you can cut away overgrown shoots and damaged/diseased branches. This process will help to shape the plant. Each cut should be within ¼ of an inch of a bud or leaf.
Fall - Complete a severe prune of the shrub.
After the foliage begins to fall off, cut off the lower stems to shape the shrub and keep a compact shape. Each stem can be cut within 8 to 12 inches from the ground.
Winter - Remove dead or damaged wood.
In late winter, remove any dead or damaged wood, as well as branches that cross each other. This will stimulate new growth in the spring.
Why Do You Prune Spirea?
Regular pruning, at least two times a year, keeps your Spirea healthy and promotes new growth. Pruning can improve the airflow in between the branches which helps to prevent fungal diseases. Removing dead branches and spent blooms allows more sunlight to reach the inner branches and branches closer to the ground.
Cutting your Spirea will help to shape the plant into a nice thigh mound. Deadheading spent blooms promotes reblooming throughout the season creating a colorful full looking shrub.
Spirea Pruning Tips
- Prune at least twice a year.
- Prune to shape the plant.
- Prune to promote blooming.
- Prune to manage overgrowth.