The goldflame spiraea, (Spiraea x bumalda Goldflame), has multi-season interest, which is enhanced by yearly pruning. Regular trimming increases reddish-bronze new shoots in spring, light greenish-yellow leaves in summer and bright pink blooms in summer and fall. This small shrub grows 3 to 4 feet tall and 3 to 4 feet wide if left unpruned, but you can easily maintain it at 2 feet with proper pruning. Prune the goldflame in late winter to early spring before new growth begins. If your shrubs are overgrown and woody, it is time for a more severe pruning to rejuvenate them.
Prune out any weak, broken or dead stems with the bypass hand pruners. Cut back all the side and top stems to within two to three buds of the old woody growth. This yearly regime will maintain your shrub's height and mounding shape and increase new shoots and flowering. If your shrub is small, only remove the weak and dead stems and lightly prune the tips.
Remove all the spent flowers during the summer with the hand pruners. Deadheading the flowers will encourage a second blooming in late summer and fall.
Cut about one-third of the oldest stems to the ground for gradual rejuvenation of overgrown shrubs, using the bypass loppers. Repeat this process every year for three years. With the hand pruners, complete the pruning by removing the weak and dead wood and trimming back the remaining stems. The shrub will look like new after the three-year process is complete.
Cut all the stems down to a few inches above ground for severe rejuvenation, using the bypass loppers. Goldflame spiraea responds well to this treatment but don't expect it to look good for about a year.
Clean your pruners and loppers before you prune, and then disinfect them with alcohol after each use. This prevents the spread of diseases to other shrubs.
Make sure your pruners are sharp so they make a clean cut and do not crush the stems Prune every year so your shrubs do not get overgrown. Do not shear your shrubs into balls with hedge shears; they are more attractive in their natural shape. This method can be used on other summer-flowering spiraea, but do not use it on spring-flowering spiraeas such as bridal-wreath spiraea.