A Snip in Time Saves Nine

 By Ron Dieter, Sunnyfield Greenhouse & Gardens

One of the most perplexing topics for many homeowners is pruning shrubs and trees. It is really fairly straightforward, once you get the hang of a few basic points. We’ll confine this discussion to deciduous flowering shrubs- those that drop their leaves in the fall. We’ll save evergreens and trees for another time.

First of all, you should not be afraid to prune a deciduous shrub. Even if you don’t know what you’re doing, these shrubs are rather forgiving and will recover from most pruning errors after a season or two. Compared to trees, they are much more tolerant of incorrect techniques. Before you grab the pruning shears however, take some time to get the answers to the most common questions about pruning.

Why prune shrubs at all?

Primarily, pruning is done to remove damaged twigs and branches and those that are unsightly or diseased. Branches that cross over and rub against another should be cut away. Pruning is also done to rejuvenate old shrubs to stimulate new growth, to encourage flowering, and to maintain twig and stem color on shrubs like red twig dogwood.

Finally, pruning is done to help keep the natural shape of a plant. Please note the word "natural". It is much easier to do minor corrective pruning to encourage the natural form of a shrub than to spend hours and hours maintaining the shapes of globes, pyramids, and rectangles. It seems to me that the homeowner who wants green spheres and boxes along the front of the house would be smart to set out some barrels and crates painted the proper shade of green. The aesthetic effect would be the same and would save all the time and labor spent forcing shrubs and evergreens to do the same job.

When is the best time to prune flowering shrubs?

The ideal time to prune most landscape shrubs is during the dormant period. In our area, it is usually done in February and March. Summer flowering shrubs- spireas, honeysuckle, beautybush, and snowberry are pruned at this time.

There is one little catch however. Early flowering shrubs should not be pruned until right after blooming. This includes shrubs like lilac, deutzia, keria, mockorange, weigela, forsythia, arrowwood viburnum, St. Johnswort, and red and yellow twig dogwoods. If you prune them now, you will not do any permanent harm, but you will remove this year’s flowers.

When is the worst time to prune flowering shrubs?

Once new growth has developed in the spring, it’s best to put the pruning shears away. The shrub has used the food stored in the roots and stems to put out new growth and needs that new growth to replenish its food supply. That’s not to say you shouldn’t cut away a few damaged branches, or remove a straggler or two, but don’t do a major pruning job on a shrub once it has gotten into full swing. Plants damaged by winds or mischief should be cared for promptly regardless of the time of year.

How often should I prune my shrubs?

You’ll save hours of work over the life of a shrub if you begin maintaining its natural form when it is young. If you keep up with your pruning, a shrub might need work only every other year to maintain its natural shape and habit. A few shrubs, such as forsythia and some spireas, may require annual pruning to keep them from getting out of hand. Once you learn the habits of your shrubs you will soon know which ones need more frequent attention.

You can save yourself a lot of work by planting the right shrub in the right space. Many plants used by landscapers as shrubs are actually small trees and will eventually outgrow their space, regardless of your pruning efforts. Yews and Junipers are such examples.

How do I learn how to prune specific shrubs?

Professor F. A. Giles of the University of Illinois has written an excellent booklet describing the three basic methods of pruning and when to use them. How to make pruning cuts properly is especially important and the booklet describes the technique in great detail. The last part of the booklet is an alphabetical list of shrubs with pruning instructions for each one. You can purchase a copy from the local extension office. Phone 853-1533 and order a copy of "Pruning and Care of Trees and Shrubs", number U5040. A general discussion of pruning can also be found in the Timely Topics section of my website, www.sunnyfield.com.