Shrubs that bloom on old wood begin to produce next year’s flower
buds soon after they finish blooming. They should be pruned as soon
as they are finished flowering so that you do not remove too many of
next year’s flowers. Those that bloom on new wood should be pruned
in winter or early spring before new growth starts.
Bright fall foliage of a Burning Bush
Burning bush is really grown for its colorful fall foliage rather
than its inconspicuous flowers, so you can prune it whenever it is
most convenient for you. Red twig dogwoods bloom, but they are grown
more for their colorful winter stems than their flowers. Since they
produce the best red stem color on young stems, they are usually
pruned in the spring. You can cut all of the stems down to within a
few inches of the ground. This will force new stems to sucker up
from the roots. Not only does this treatment produce the most
colorful stems, it is also a great way to keep these vigorous plants
If any of these plants are very large and overgrown, consider
sacrificing the flowers and pruning them when they are dormant.
Early to mid-March is ideal for the plants and the person doing the
pruning since we can have very nice weather at that time of year.
Severe pruning is not as stressful for plants when they are dormant.
If the shrubs are healthy and vigorous, it is fine to prune them
back into shape in one session. However, very old plants or those
that are not healthy and vigorous should have severe pruning spread
over a three year period to reduce the impact of removing so much
Azaleas bloom on 'old wood'
It is best to have all pruning finished by mid-July. Pruning forces
new growth on actively growing plants, and if that happens too late
in the season, the new growth can be killed by cold winter weather.
Dead branches or stems should be removed whenever you notice them,
regardless of the season.