Specific types of pruning may be necessary to maintain a mature tree in a healthy, safe, and attractive condition.
- Cleaning is the removal of dead, dying, diseased, weakly attached, and low vigor branches from the crown of a tree.
- Thinning is selective branch removal to improve structure and to increase light penetration and air movement throughout the crown. Proper thinning opens the foliage of a tree, reduces weight on heavy limbs, and helps retain the tree’s natural shape.
- Raising removes the lower branches from a tree to provide clearance for buildings, vehicles, pedestrians, and vistas.
- Reduction reduces the size of a tree. Reducing a tree’s height or spread is best accomplished by pruning back the leaders and branch terminals to secondary branches that are large enough to assume the terminal roles. Compared to topping, reduction helps maintain the form and structural integrity of the tree.