In fact, some of these products may retard healing. Thinning is used to thin out branches from a shrub that is too dense. It is accomplished by removing most of the inward growing twigs by either cutting them back to a larger branch or cutting them back to just above an outward facing bud. On multi- stemmed shrubs, the oldest canes may be completely removed. Heading back is removing the end of a branch by cutting it back to a bud and is used for either reducing height or keeping a shrub compact.
Rejuvenation is the most severe type of pruning and is normally done during the dormant season.
It may be used on multi-stem shrubs that have become too large with too many old branches to justify saving the younger canes. This works well for spirea, forsythia, pyracantha, ninebark, Russian almond, little leaf mock orange, shrub roses and flowering quince. Both termites and ants are able to swarm and may have wings during part of their lives. Since these insects are close to the same size, people often misidentify flying ants as termites. Since flying ants do not attack wooden structures like termites, it is helpful to be able to tell the difference.