The best time to prune trees and shrubs is from now until when the leaves start budding out – in other words, when they are dormant during the cold weather. Pruning would have been fine in January, too – for the plants, that is. Deep snow, cold temperatures and strong winds would have made it tough for the human doing the pruning.

Often I make an exception for spring-blooming trees and shrubs like forsythia and lilacs, arguing that pruning now reduces the spring bloom. But they can be pruned now. Losing the bloom won’t hurt the plants, and the blossoms will be fewer for only a year.

The lack of leaves makes it easier to see the shape of the overall tree as well as the individual branches – which makes pruning easier.

People prune trees and shrubs (“woodies” is a term that gardeners use that covers both) for many reasons: to get rid of dead, damaged or defective branches; to keep a tree smaller and a more pleasing shape; and to keep woodies healthier.

You need three tools for pruning: a hand pruner for cutting branches up to about a half-inch in diameter; a lopper for cutting larger branches, up to about 1.5 inches; and a pruning saw for cutting everything else. Make sure they are sharp before you start. Hand pruners are shaped like scissors but are more powerfully constructed. And, no, you cannot use a carpenter’s saw for pruning. Buy a pruning saw, and you will be glad that you spent the money.

Next, study the woody to assess its problems. Obviously, start by cutting out any branches that are dead; they usually look gray and dried.

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Now cut out anything that is dangerous or inconvenient – perhaps something that was partially broken in last fall’s big storm or a branch that sticks up above your dining room window. If branches extend into or over walkways or driveways, are hitting your house or heading toward utility wires, they go next.

It’s time to cut any branches that are touching or crossing, which causes damage to the branches when they rub together in the wind.

The next cuts will improve the health and beauty of woodies. Most will look better and be healthier when they are not a mass of leaves. Leaves dry out faster after a rain and they get more light if the branches have space between them.

In this stage, the first branches to prune are the ones that go straight up, often called water sprouts. Second, cut branches that are going downward. Third, cut off all branches that are growing from the outside toward the center of the plant. All those branches are less pleasing visually than ones that start near the center and branch outward.

When cutting branches, always cut as close to the collar (a ring of bark near a trunk or larger branch) as possible. Such cuts avoid unsightly stubs, and the cut will heal faster.

Some shrubs, such as lilac and forsythia, have multiple stems or trunks coming out of the ground. On those plants, cut some of the largest, oldest stems at ground level first. The smaller stems will have more vitality and produce more flowers.

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Apparently, years ago, lilacs were grafted or people believed they were, so a “pruning rule” said you need to cut out all the small stems coming from the ground because they will cause the lilac to “revert.” I have no idea where that idea came from, and it isn’t true. If you follow that rule you will end up with very old lilacs that can be 10 to 12 feet tall. You’ll get fewer blooms as well.

On the shrubs with multiple stems from the ground, the thickest branches will be the tallest, so pruning out the thickest branches will keep the shrub from getting too tall. In addition, it will allow new branches to sprout from the ground. Without younger growth, you could end up with a lilac, for example, having naked trunks rising 8 feet up without blossoms. You need younger growth to have lower and more plentiful blossoms.

If you do have those long, naked stems there is a quick solution – although you will go without blossoms for a year or two. Cut everything off down to ground level, which the late, great Cass Turnbull, pruning guru, called “radical renovation.” The plants will come back healthier than ever.

Everyone should follow two rules when pruning.

First, walk around the tree after every major cut, look at it and then decide where the next cut should be made. You may be tempted to make two cuts before circling the shrub again. The result could be a lopsided woody or a huge hole where you don’t want it. That will take years of growth to fix.

Second, if you know you want to get rid of the end of a branch and think you probably want to get rid of all of it, cut off just the end of it first. It’s not that much extra work to make two cuts, but it’s impossible to reattach a branch to the tree. You may find that one cut, getting rid of the end, is all you need.

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When cutting off part of a branch, make the cut at the joint of two branches. Leaving a stub is unhealthy for the tree, in addition to being ugly.

Pruning really is a project where you can teach yourself as you go along. If you make a mistake, the tree or shrub will heal itself in a couple of years, and you will have more experience when the next pruning is required.

There are only two things to be afraid of: ladders and chainsaws. If your pruning job needs either one, get a professional.

ABOUT THE WRITER

TOM ATWELL is a freelance writer gardening in Cape Elizabeth. He can be contacted at 767-2297 or at: tomatwell@me.com.


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