ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Thursday, February 29, 1996 TAG: 9602290038
SECTION: CURRENT PAGE: NRV-2 EDITION: NEW RIVER VALLEY
COLUMN: Hoein' and Growin
SOURCE: SARA THORNE-THOMSEN
Even in winter the health and well-being of your landscape is important.
On pleasant days between snow storms and cold snaps, we look at the ground to see if our early crocuses are in bloom or if the alternate freezing and thawing weather has pushed any perennials out of the ground.
Push ``heaved'' perennials back into the soil so that the exposed roots will not dry out and die. Add some mulch to protect plants from further undesirable exposure.
Take the time to examine the limb structure of your shade and other deciduous trees. Winter is a good time to remove tree branches that excessively shade herbaceous flower beds because limbs will not damage the plants as they fall.
It is also a good time to identify and remove dead, diseased, and storm-damaged branches.
Last year, I hired a certified arborist to advise me about a silver maple and a white pine that had been damaged a few years ago by an ice storm. The weight of the ice created a spectacular explosion set off by a limb of the silver maple falling onto the ice-laden branches of the pine.
In their weakened condition, I feared they might fall on house, cars or people (including me!). After explaining why both trees were injured beyond recovery and pointing out that the silver maple was also diseased, the professional recommended removing both, which I had him do.
Following this arborist's advice, I shall replace them this April with a red oak. It will better endure the ravages of winter as it grows into a handsome shade tree.
A certified arborist is a tree professional who has earned this credential from the International Society of Arboriculture by passing each part of a rigorous 10-part comprehensive examination that covers tree nutrition, tree biology, tree identification, pruning, and safety.
Certified arborists have a minimum of three years of field experience or two years field experience and a college degree in a related field. They renew their certification regularly by completing arboriculture-society requirements for continuing education to upgrade their skills.
Although a certified arborist may cost more than a tree cutter with a chain saw and truck, it is important to remember that you will reap the benefits of money spent on the health of your trees. You can find an arborist by looking in the Yellow Pages.
I hired a professional because I wanted an educated assessment of the condition of the trees. I realized that I had neither the equipment nor the skill to attend to large trees.
Before you plan to cut down a tree or prune it yourself, assess the situation. How large is the tree? How much pruning will have to be done in the tree's crown or top area? Can you reach the branches without endangering your life and limbs? Can you make a proper pruning cut so the tree is not damaged further?
If the situation is beyond your capabilities (and any crown pruning almost certainly is), call a certified arborist to schedule maintenance while trees and underlying landscape plants are dormant.
If you can do the pruning yourself, it is important to use proper pruning techniques. There are two basic types of pruning cuts: thinning cuts, the removal of branches at their points of origin, and heading cuts, the trimming back of lateral branches and removal of terminal buds. On deciduous trees, use thinning cuts because they stimulate growth throughout the tree. Don't use heading cuts, because they stimulate unwanted growth of weak suckers at the pruned points.
Also, heading (or topping) disfigures older trees and exposes large areas of bare wood to disease, insects, and even sun scald, all of which weaken the tree and increase the likelihood of storm damage both to the tree and whatever happens to be beneath it.
When pruning large limbs (anything over 11/2 inches in diameter), use a three-part cut to prevent the limb from falling before it is fully cut and tearing bark from the trunk, thereby creating a wound that can become an entryway for insects and diseases.
First, make an undercut 6-12 inches out from the trunk by cutting, from the bottom up, one third of the way through the limb. Next make a second cut from the top down through the limb about 3 inches farther out from the undercut and allow the branch to fall away.
The remaining stub should be cut at the gnarled halo at the base of the limb. This swelling, called the branch collar, produces hormones that help heal the wound and make it unnecessary to coat the cut with tree paint or wound dressing. Don't cut the limb flush to the trunk. You will lose the benefits of the collar.
Finally, cut away and remove any vines that are strangling your trees, such as bittersweet, wisteria, wild grape, poison ivy, Virginia creeper, or Japanese honeysuckle.
A well-tended shade tree provides welcome summer shade, enhances your landscape, and increases the value of your property. Nourish it as you would a valued friendship.
Sara Thorne-Thomsen is a Master Gardener.
LENGTH: Medium: 93 linesby CNB