Trees and shrubs are a dynamic, ever-changing part of your home landscape. As living organisms, they rely on you for the kind of care that will keep them healthy and performing, to provide shade, showy spring flowers, fragrance or spectacular fall color. It may still be winter, but now is the time to examine your yard’s woody plants to see if they need pruning.
“Winter is a great time for people to prune. They can see the whole structure of the plant,” says Doris Taylor, plant information specialist at the Morton Arboretum. Pruning from February through early spring allows dormant trees and shrubs to develop a callus around the cuts, helping them to heal more quickly than at other times during the year.
Pruning is done for many reasons, but one purpose is to maintain a woody plant’s health and vigor. “You want to remove diseased, dying or dead branches. And you prune to remove crossing branches that rub against one another,” Taylor says. Chafing in the wind, crossing branches can abrade and injure their bark, resulting in wounds through which disease and pests can enter.
Winter is also a good time to remove branches that have grown across sidewalks, impeding foot traffic and creating a potential hazard. Unsightly suckers, the small stems that sprout from the base of trees such as crabapples, should be removed along with water sprouts, fast-growing stems that rise vertically from large, older branches. Suckers and water sprouts detract from a tree’s overall appearance.
“You may have a shrub that has a floppy branch, a shoot that takes off further than the others. By heading back–removing part of a branch that is out of balance with the rest of the plant–you can control the shrub’s overall size and appearance,” Taylor says.
In her new book, “The Landscape Makeover Book: How to Bring New Life to An Old Yard” ($21.95, Taunton), Sara Jane von Trapp notes, “a shrub with a tangled mass of vegetation has poor air circulation, which creates a nice, moist home for diseases and insects.”
An older, neglected shrub can often be restored to vigor with rejuvenation pruning, which requires cutting all its stems or canes to ground level. Shrubs that respond well to rejuvenation pruning include forsythia, weigela, privet, lilac, viburnum, honeysuckle, spirea, hydrangea, caryopteris and buddleia.
“If you have a nice big old lilac that hasn’t been pruned in years, you might need to rejuvenate it all the way to the ground. However, if you have a spring-flowering shrub that’s not in bad shape, you might want to prune it right after it flowers. Many shrubs develop their flowers on the previous year’s growth and pruning before they bloom in spring will remove the flower buds before you have a chance to enjoy them,” Taylor says.
While pruning can reduce the size of an overgrown shrub, it also helps a plant produce new growth. The brightly colored branches of red- or yellow-twig dogwoods create impressive winter interest. But without pruning, their colorful stems eventually fade to muted tones of gray or tan. These shrubs benefit from an annual practice called renewal pruning, which will keep their stems vibrant all year long.
“With renewal pruning, you cut down one-third of the old stems each year because the new branches have the best colors. Renewal pruning can also improve flowering on ornamental shrubs,” Taylor said. Renewal pruning is best done now, during the dormant season.
Mature trees may need only occasional pruning to remove dead or diseased wood. When pruning some trees like maple, walnuts or birches in late February or March when the sap is flowing, Taylor says, the sap will ooze from the pruning cut. “It’s called bleeding and is unsightly but it doesn’t harm the tree.”
Other trees that may bleed during winter or early spring pruning include beeches, hornbeams and yellowwood. This can be avoided or lessened by pruning these trees in spring after their leaves have fully opened.
Taylor favors hand pruners that can be used on pencil-sized branches that are no more than 1 inch in diameter. Larger, heavy-duty loppers may be used on branches up to 3 inches wide. Beyond that, Taylor recommends using a special pruning saw. All of these tools are available at home improvement stores and garden centers.
“If you have to go up a ladder, you might think about having a professional arborist do it. The weight of a 3-inch limb is quite heavy,” Taylor cautions.
Most evergreens have only one growth spurt each year and caution should be taken when attempting to prune them Taylor says. “Some, like yews, are more forgiving than others. They’ll generate new growth on older wood. If you lop off the top of a pine, it won’t continue to grow there but will send up another leader [branch], Taylor says.
Common in foundation plantings and hedges, yews are often sheared for a formal look. Yews may be pruned in late winter or early spring to maintain their size. An annual shearing should be done after the new growth appears in spring and through August as needed.
Another common foundation plant, junipers may benefit from selective pruning to correct their shape or reduce their size. Severe pruning or shearing is not recommended because junipers develop a “dead zone” in the center of the plant where there is insufficient light. Pruning branches back to the dead zone will prevent new growth.
Take into consideration the natural shape of the shrub and prune it to keep that shape. Foundation plants formed into small yellow and green meatballs are unnatural and don’t do much to enhance the curb appeal of most homes. Your pruning should be in keeping with the natural tendencies of the plant von Trapp says. She cautions, “If a plant wants to weep, do not cut off its trailing branches, or it will be a never-ending battle and the plant will never look right.”
After pruning forsythia, crabapple, flowering almond or lilac, bring their branches indoors for forcing an early display of flowers. Placed in a container of water and set in a cool spot away from direct sunlight they’ll reward you with a bounty of blooms in two to three weeks.
Tools of the trade
If you have a large yard with many trees and shrubs, and enjoy caring for them, inexpensive pruning tools won’t last long and you’ll end up having to frequently replace them.
There are two types of hand pruners: anvil and bypass. An anvil pruner uses one blade that comes to rest on the lower, wider blade. A bypass pruner uses blades with a scissors-type action that crosses each other and creates a clean cut.
When you’re buying pruners, try them out for weight and comfort for the size of your hands.
Don’t smash or tear the branch or twig as you prune and avoid peeling the bark away from an incomplete cut. No matter how small the cut, pruning creates a wound on the plant. Clean, sharp tools help make tidy pruning cuts that allow the plant to heal. Because diseases can be spread from one wound to another, von Trapp recommends carrying a cloth and spray bottle filled with rubbing alcohol along with your tools so you can disinfect the blades between each cut.
Pruning paints, once thought to help seal the wound, are not necessary and may seal in disease.
Loppers are large versions of hand pruners. The handles are usually about 2 feet long. Padded handles can make the job comfortable if you have a lot of pruning.
Pruning saws are designed to cut fresh green wood. Unlike the teeth on a typical carpentry saw, a pruning saw’s teeth are shaped to resist gumming from sap.
Some have straight handles, others curve and some fold for easy transport.
A pole pruner is nice for hard-to-reach branches. The saw is extended on a long, telescoping handle.
