CLEANING consists of removing dead, dying, sick, crowded, weakly attached and weakly attached branches from the top of a tree with little vigour. This type of cutting requires no shears. To do this, you'll pinch a bud with your fingers. This is done on the terminal buds to eliminate growth and encourage the plant to grow bushy rather than leggy.
Pinching, which is usually done on small shrubs and flowers, helps to shape the plant and control its growth. Most gardeners will be familiar with this type of pruning. According to the Pennsylvania State Extension, dead pruning is a pruning process whereby old shoots and seed heads are removed from the plant to promote new growth and new flowering. As the flowers wither, pinch or cut the flower stalks below the spent flowers and just above the first set of healthy, full leaves.
This effort eliminates wilted flowers and encourages plants to redirect their energy to new growth. Thinning cuts remove entire shoots from a plant to decrease the overall thickness of its foliage. This type of cut is not done to stimulate growth; on the other hand, thinning removes entire shoots, stems and branches where they meet the larger main branches. Thinning does not usually change the shape of the plant, but it does produce fewer branches overall, which can increase air circulation through the foliage.
According to Colorado State University Cooperative Extension, reduction cuts remove a larger branch or trunk and return it to a smaller lateral branch. Reduction cuts are commonly used to train young trees. They are also the only type of cut that significantly reduces a tree's height. It's not a good idea to make these cuts on mature, established trees because they can destabilize them.
The removal of dead, dying and diseased branches is the most basic but underutilized type of pruning. In the tree care industry, it's known as “crown cleaning.” This process seeks to open the canopy by selectively removing branches from young trees throughout the canopy. There is a strong emphasis on eliminating weak branches. The industry refers to this as “corona thinning”.
