How to Trim a Spirea Shrub

Overview

A hardy, fast-growing shrub, spirea, or bridal's wreath (Spiraea spp.) grows to a height of 6 to 10 feet but can spread up to 20 feet wide. They grow in sun or partial shade and are tolerant of all types of soil as well as urban conditions. The classic bridal's wreath bush is the variety 'Vanhoutte,' which produces masses of clusters of small white flowers in spring. Japanese varieties (Spiraea japonica var.) grow much shorter and usually have pink flowers. A notable Japanese variety called 'Shirobana' produces white, pink and red flowers on the plant all at the same time. 'Shirobana' grows only 2 to 3 feet high.

Step 1

Remove any branches that are dead, diseased, growing across or rubbing against another branch.

Step 2

Remove the oldest and any weak canes or branches by cutting them off at ground level with the pruning clipper. Use the saw if the branches are large in diameter.

Step 3

Thin out the remaining canes, removing about one-fifth to one-fourth of their total number. This will give the remaining canes room to develop and send out vigorous new growth that will eventually produce flowers.

Step 4

Prune off dead flower heads after the shrub has finished blooming. Japanese varieties, which bloom on the current year's wood, often produce a second, smaller flush of bloom when the flower heads are promptly removed, according to Clemson University Extension.

Things You'll Need

  • Pruning clippers
  • Pruning saw

References

  • University of Arizona Extension: Pruning Shrubs
  • Clemson University Extension: Spirea
Keywords: trim spirea shrub, prune spirea shrub, prune bridal's wreath

About this Author

Sharon Sweeny has a college degree in general studies and worked as an administrative and legal assistant for 20 years before becoming a freelance writer in 2008. She specializes in writing about home improvement, self-sufficient lifestyles and gardening.