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Tips for the Compleat Gardener: In the beginning was pruning


The crazy weather of recent weeks has been doing some of nature’s pruning in the neighborhoods around town, dead limbs dropping under the weight, trees split apart because unbalanced growth makes them vulnerable to storm damage.

To repair what has been done by weather often means cleaning the tear by cutting it fully off with a pruning saw or lopper, but the more prudent action is to incorporate regular pruning into your landscape care. Work on larger trees is best done by specialists with climbing skills and insurance but attention to young specimens from the start can help create balanced tree growth and good health.

To know how to properly prune any specimen one must first understand its basic structure. Most trees, with the exception of oaks and conifers which have long taproots, have a fibrous mat of roots spreading out from the trunk like an apron that can be as much as three times the width of the canopy, or leaf-bearing structure of the tree above ground.

How you prune affects the roots which provide the tree with an anchor and food drawn from the soil. They also store energy gathered from the leaves during photosynthesis. The new growth of roots in spring begins the awakening but this is stimulated by a chemical message sent from the buds.

Every tree has its own shape; generally pyramidal, round or vertical. When you seek to prune a tree first take the time to carefully walk around the specimen and ascertain its natural growth style. The goal of pruning is generally to control growth, shape purposefully to fit your style, or to stimulate bud production and some times to cut out damage.

If you plan to prune any of the following trees, do so immediately while they are still dormant because when they awaken they bleed profusely if cut. These are the “bleeders” – birch, elm, flowering dogwood, grape, maple, walnut and yellow wood. You will know right away if you should stop because your tools will be getting wet.

Trees have trunks, branches, limbs and shoots. A shoot is technically a one year old un-branched growth that could grow in any direction. Uncut these will develop into branches.

A basic rule of thumb when pruning is that no branch should cross another bark to bark. Look carefully at the tree to determine which branch is following the natural growth pattern of the tree and remove the other.

Around a limb is a branch collar, you will see this in various thicknesses where the branch joins the larger branch or trunk. This collar contains all kinds of special cells and tree chemicals to fight off infection and protect the larger tree from invasion of pathogens. Take care not to cut into this collar when removing a branch or limb.

Water spouts are obvious when observing a tree, they are usually smoother skinned and paler than the regular branches of the tree, typically growing rapidly skyward. These should be pruned off while the tree is dormant because removal during active growth in spring tends to stimulate more to grow. Waiting for the relative dormancy of late summer seems to work well for avoidance of re-growth.

Many nursery specimens are actually grafted on sturdier root stock and often that root stock sends up off shoots of its own, rising from the area around the tree’s base like a forest of interlopers. These must be removed for the health and general aesthetic value of the tree. You will probably need to do this regularly on a tree prone to the problem.