Estimated read time: 3-4 minutes
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
Electric pruning shears rank just slightly below the chain saw in the macho tool pecking order. They are also only slightly more precise.
"I know more time is involved in carefully pruning as opposed to running the shears along the side of the driveway or sidewalk cutting everything that's either green or woody," says Jerry Goodspeed, Utah State University Extension horticulturist. "But please, do not succumb to the temptation."
Most evergreen shrubs are not meant to be pruned in the shape of a half moon with one side flat and the rest of the plant left natural, he says. Many gardeners can't make up their mind between a formal hedge and a natural shrub. One side is pruned flat and formal, the other side is left to grow and flourish on its own.
"This is not natural and can even be classified as cruel and unusual punishment," Goodspeed says. "The cruel part being how the plant looks, the unusual punishment being what neighbors are forced to view."
The most important thing to remember when pruning evergreens is the timing, he explains. All evergreens need to be pruned when the plant is actively growing. This usually happens in May or June. If they are pruned while growth is dormant, there is a chance of removing the growing points and deforming the plant.
Pines and most other evergreens are pruned using the candling method, he adds. The new growth that emerges each year is called the "candle." This growth is succulent and has many growing points where the needles are being formed and beginning to grow. After growth begins, about half of the candle can be pruned off or pinched back. This will reduce the height and create a fuller shrub.
This method is most commonly used when controlling the growth of Mugo pines and other low growing pines, spruce and firs, Goodspeed says. Some conifers have short candles, such as a dwarf Alberta spruce and a bird nest spruce. With all the new growth, it would be nearly impossible to pinch out every candle.
"When a juniper begins to grow out into the sidewalk or driveway, there is a great temptation to just cut a straight edge on the plant, giving it the appearance of being a fence or wall and not a natural plant," he says. "However, pruning and trimming evergreens to keep them within the bounds of a landscape are accomplished correctly by removing selected branches and twigs back to a branch or trunk. By cutting off a few of the overgrown branches every year, the plant will remain smaller and still maintain its natural shape."
The only pruning that should be done on larger evergreen trees is to remove the lower branches, he adds. Topping a tree will not stop its growth, it will only make it look funny and unnatural and encourage insect and disease problems. If a tree has lost its leader (the top growth), a new one can be developed by tying a lower branch to a vertical stake placed in the tree. Most conifer evergreens look best if there is only one leader, so pick the best and remove the rest. The tree will look odd for a year or two but will eventually grow out of this awkward stage.
Of course the best way to prune an evergreen is not at all. Make sure the plant size will fit the space before buying it, he says. A properly placed shrub or tree needs little, if any, pruning.
By Dennis Hinkamp - Utah State University Extension