Abstracts

Abstracts

BUCKINGHAM, FRANK. 1986. Felling trees--safely. Grounds Maintenance 21(9): 34, 36, 38.

Cutting trees can be a pleasant challenge or a dreaded chore. If you must remove trees whose limbs hang over buildings or power lines, or trees that are likely to damage other desirable trees or property when they fall, the task becomes critical. Unless you are an experienced tree cutter and are certain you can safely remove trees in tight situations, call in a professional arborist. Wear clothing that is snug but not too tight. Before starting to cut down any tree, decide which way you want it to fall--and which direction the tree is most likely to fall on its own. Clear an escape route (preferably two routes) so you can get away from the tree when it starts to fall. Make your first cut horizontally on the crownlean side of the tree-the side to which you want the tree to fall. Now, make a second cut at the 35-degree angle to the first cut; remove the loosened wedge of wood. Make the final fell cut from the other side of the tree, parallel to the first cut in the bottom of the notch.

COLLMAN, SHARON J. 1986. Winter injury. Grounds Maintenance 21(10): 10, 12, 14, 18, 20.

The symptoms of winter injury depend on the plant species, condition and factors that caused the injury. In diagnosing any plant injury, there are two areas to examine-symptoms and signs. Low- temperature injury is usually manifested by several symptoms. First, extreme cold will cause the leaves, twigs, stems and even roots to freeze. Symptoms of this kind of injury are severe wilting, complete blackening or browning of the leaves and stems, and general collapse of above-ground plant parts. Occasionally, only the flower buds of certain plants (like some rhododendrons) are killed. Freezing temperature in spring after the buds have begun to swell will often result in abnormally twisted and curled new leaves. Some winter injury is actually drought injury. On sunny days with drying winds, water is lost from the leaf surface. Because the soil is frozen, the plant cannot replace the lost water. The foliage of certain conifers, such as some arborvitaes, cryptomerias and junipers, will change their normal green color to brown or purple. Once a period of extremely low temperatures has occurred, wait until spring before attempting remedial measures.