Q. What is “tree topping” and is it a good idea?
Tree topping refers to the practice of removing or cutting back all or most of the large branches in mature trees, leaving short stubs which will eventually put out numerous new sprouts. Experts generally agree that this is usually not a good idea, for several reasons:
- Tree topping starves the tree of its food supply. With fewer leaves to carry out photosynthesis, the tree is starved of the sugars that it needs to survive.
- The tree is shocked. The tree crown no longer screens the trunk and lower branches from direct sun. This may result in damage from scorching. Also, shrubs and other nearby plants previously sheltered by the tree crown may be damaged if they are shade-loving species.
- The tree will be more susceptible to pests. The large stubs of topped trees are slow to heal. This leaves them susceptible to insect and fungal invasion.
- The new shoots that develop from the cut limbs grow very rapidly. They are more numerous than the original growth; bunches of small branches grow from the site of the cut. The result is often a tree that is larger and growing more rapidly than previously. Although the reason for topping is often to reduce the size of the tree, the procedure has the opposite effect.
- Topped trees are often very ugly, as they never regain the natural shape of the original tree.
- Although the cost of topping a tree may be less than proper pruning, the long-term cost may be more if the tree dies or if neighboring plants are affected. Also, future maintenance may be higher because of the rapid growth of the new shoots.
The alternative to tree topping is selective pruning. Crown-reduction pruning involves cutting back large branches to laterals that are at least 1/3 the diameter of the branch being removed. Also, a light pruning every few years will help to keep trees in good condition. It may be too late now, but choosing a tree whose size is appropriate to the site will reduce future problems.
A note on pollarding:
Pollarding is often confused with topping. In pollarding the branches and shoots are cut back to the same point every year (or two). This procedure is less harmful to the tree than topping because a balanced tree results. Pollarding is popular in Europe and many pollarded trees there are now hundreds of years old. It was originally developed to provide a source of food for animals or wood for many purposes. Some species, e .g. London plane tree (Platanus × acerifolia), willows (Salix spp.) and mulberry (Morus spp.), are particularly suitable for pollarding.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service