When I discuss pruning small trees and shrubs such as Japanese Maples and Crape Myrtles with my clients, I use the term fine pruning. I would define fine pruning as trimming trees and shrubs to improve their shape, health and size. Every urban or landscape plant needs to be pruned at some point in its life so that it will become a healthy mature specimen plant.
Japanese Maples require ‘fine pruning’; technical limb removal that improves the health of the tree.
Trees and shrubs can be divided into two groups; single stemmed plants that utilize a central leader (a single trunk with a bud at the end that has superiority over all other limbs in the tree as the dominant branch) and multi-stemmed plants that have many trunks (no single branch is dominant). Pruning these two types of plants requires different approaches.
Single leader trees, often referred to as shade trees must be pruned periodically. Branches that try to compete with the leader for dominance should be removed. Maples for instance are notorious for forming ‘double leaders‘. Double leaders (two codominant trunks) can eventually fail causing one or both of the trunks to break away from the tree.
Dead wood should be periodically pruned out of the crown of a tree (the bole or aerial portions of the tree) in a process known a crown cleaning. Sometimes trees become too dense and need to be thinned in a process known as crown thinning. If a tree hasn’t been properly cared for or if something has made the crown of a tree lopsided we might shape it in a process known as crown balancing. Excessive weight on one side of a tree can actually pull a tree down over time.
Large trees can be pruned at any time of the year. The optimal time to prune shade trees is during the dormant season when all of the leaves are off of the tree. It is much easier to see what limbs should be removed when there are no leaves on the tree.
Pines and other conifers should be pruned in the winter to avoid attracting pests such as pine beetles.
Avoid planting trees to close to structures! This Japanese cryptomeria has the potential to get to be 70 feet tall and 50 feet wide! 4 feet from the foundation is too close.
Shrubs or multi-stemmed plants also need light pruning to maintain their shape and size and improve their health. Shrubs can become too large for their allotted space. The nice thing about shrubs is that they can be maintained at a certain height. Sometimes though, shrubs are allowed to get too large. Who would have ever guessed twenty years ago that the Dwarf Burford Holly planted on the corner of the house would get to be twenty feet tall one day? Excessively large shrubs are cut back in a process known as renewal pruning. Overgrown shrubs can be cut back to 18-24” above the ground in late winter or early spring to reduce their size.
Flowering shrubs and small flowering trees should be pruned after they finish flowering. Timing is important to avoid removing next year’s flowers. Azaleas are pruned in early summer, hydrangeas in late summer and camellias in late winter as examples.
Pruning is a skill that when performed properly can improve the health of a plant. Winter is the best time of year to prune most plants in the landscape so either do it yourself or hire a professional. Either way your plants will thank you for it by performing and looking their best.