Outdoors: Five things to know about trimming trees and bushes

Even though it doesn’t feel like it yet, fall is on its way. Soon blazing heat will give way to cool breezes, changing leaves and probably a few tropical storms.

Master gardeners like John Trivits like to be one step ahead of the changing seasons, preparing themselves and their fellow green thumbs for the next phase in the gardening cycle.

Before long, it will be time to prune those trees and shrubs that have been blooming all summer. As the owner of an up and coming apple orchard in Laurel, it’s a subject Trivits knows all about.

1. Prune with a purpose

When dealing with fruit trees and ornamentals, Trivits said it’s important to know what you’re trying to achieve with pruning.

Trees primarily should be pruned to keep them from growing too large for their purpose or environment, to keep the branches strong and structurally sound, and to promote healthy flowers and fruit that are more resilient.

Trivits’ rules for pruning also apply to shrubs, particularly when it comes to reducing the level of heat and moisture inside the canopy — to much can promote fungus and disease.

“You can apply this to anything you are pruning,” he said. “If you get a shrub with all these [branches] touching inside, it dies.”

2. When choosing tools, simplify

On the rack at the hardware store there are all kinds of shears, loppers and saws for tree and shrub trimming, but Trivits recommends one simple tool: the scissor-like “bypass” pruner.

“You don’t need a lot of tools. I have a shorthanded bypass pruner and a longhanded bypass pruner,” he said.

He prefers the two-blade scissor design to the anvil-type pruner, which has one blade that pushes against a straight metal piece.

Trivits also said it’s essential to keep pruning tools sharp, but they don’t have to cost a lot.

“I try to buy a decent set of pruners for $12 or $15. I lose them before they wear out,” he said.
Chainsaws, he added, aren’t to be used to prune ornamental trees — they’re strictly for cutting trees down.

3. Know what to cut, where and when

Most tree pruning should be done in the winter when trees are dormant, but trimming can begin as soon as most trees lose their leaves. Most shrubs and bushes can be trimmed after they’ve flowered.

Waiting until dormancy ensures the plant is not going to expend its energy on sprouting new growth to replace what’s been cut off, Trivits said.

When pruning, concentrate on branches that grow straight up, straight down or back into the center of the tree. Also focus on branches that cross or touch, which can rub off bark and make the tree susceptible to disease.

Dead branches, stems or limbs can be pruned any time of year. Often, dead limbs can be infected with bacteria or fungus that must be cleared away.

“Dead or damaged limbs should be removed as soon as you see them,” Trivits said. “If I don’t know why it died, it goes in the burn pile.”

4. Make a proper cut

Trivits said it’s essential to prune with precision. Sloppy trimming can cause more harm than good to a tree or shrub.

Using those sharp pruning tools, trim as close to the main branch as possible to promote healing. A stub left on the branch will die and rot, leaving the live part open to infection, Trivits said.

Always make cuts on an angle so the open wound will shed water and discourage the growth of fungus or bacteria.

When cutting back dead growth on trees or shrubs, Trivits said it’s vital to cut well past the dead portion of the branch.

“You have to go back beyond the dead growth. You’re actually cutting the live growth,” to promote healing, he said.

Trivits and other master gardeners do not recommend treating pruned trees with wound paints or sprays. The best way for a tree to heal is naturally, he said.

5. Mother nature is in control

Above all, Trivits said the best way to learn good pruning habits is by doing.

After pruning, monitor trimmed trees and shrubs to see how they react. Stay on top of new growth and watch for dead limbs and indications of disease, like discolored leaves, marred fruit or lack of flowers.

But even with diligent pruning efforts, Trivits said Mother Nature can always throw a curve ball.

“A lot of this stuff I’ve learned the hard way,” he said. “Even with all the research I’ve done, sometimes you’ve got to let a tree be a tree.”

Email Doug Denison at doug.denison@doverpost.com.