Beware of pruning shrubs too much

By now, many of you have put away the pruning shears in favor of tools that receive much more use at this time of year. The rake, the hoe and the lawn mower are in their heyday, not the loppers and the hand saw. But don't file them away entirely or you'll be missing many chances to improve the health and appearance of your yard and garden.

The early spring flowering shrubs have finished blooming, along with many of the second wave of bloomers like the lilacs. If these plants need more than just a trim to get them in shape, now is the time to get to it or you will likely not see a bloom on those plants if you wait to prune them. This class of shrubs flowers on wood that was grown during the last year's flush of growth directly after blooming. They are in that state of vegetative growth now and, depending on the weather, may not continue to grow much longer. The flower buds for next year will be on the growth that is being produced currently. For that reason alone, now is the time to get the pruners out.

Another prime motivator to get any major work done now is the fact that we are heading into those blistering summer days that are hard on gardens and gardeners alike. By cutting away lots of outer foliage on a plant, one exposes leaves and branches and possibly some of the trunk to the searing effects of the sun. Sunscald can occur on even the most heat-tolerant species when formerly shaded parts are opened up to direct sun.

What, then, is the proper way to prune at this time of year? The simple answer is to let the plant's natural shape dictate your pruning style, but that's one of those easier-said-than-done adages. I try to classify shrubs into easy-to-remember shapes and try to achieve that look. As an example, let's look at a typical spring flowering shrub, the forsythia, for our inspiration.

The forsythia is a vase-shaped shrub that resembles the letter "V" when grown well. The trouble in our gardens is that often, the plant grows too large for its allotted space and the gardener tries to control it by pruning. Going out on a fine winter day, said gardener, appropriately armed with sharpened steel, promptly whacks the plant in half, or more, down to ground, and walks away satisfied that he has reduced the height of the plant significantly. However, the effect is temporary and illusory at best. Rapidly re-growing a thicket of new branches from the end of the cut branches, not only does the plant return to its former size, it now has an unnatural shape with curious branch shapes. It's not long before there is another visit by the gardener who now cuts more severely in order to get control over this monster.

The proper course of action would have been to remove any overly long branches back to the ground, or at least to the main trunk. This would have preserved the naturally arching branches while keeping the plant realistically smaller. If you need to prune more than that to keep it in line, you need to replace it with a smaller shrub!

Plants that are particularly prone to sunscald and scorch after spring or summer pruning are the maples — especially the Japanese maples — dogwoods and members of the rhododendron family. It doesn't mean that one can't shape these plants at this time of year, just limit your pruning to thinning out overly thick shaded interiors and cutting back to foliage that has already been growing in lots of sun.

I find that wood removed from plants at this time of year is more reluctant to grow back than winter-pruned wood. This makes it the ideal time to lightly shape and reduce the size of fruit trees in the home orchard. Just keep in mind the principals involved, and you and your plants will be better off if you carry your shears with you every time you visit the garden.

Stan Mapolski, aka The Rogue Gardener, can be heard from 9-11 a.m. Sunday mornings on KMED 1440 AM and seen in periodic gardening segments for KTVL Channel 10 News. Reach him at

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