Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SUNDAY, April 9, 1995                   TAG: 9504110094
SECTION: HOMES                    PAGE: B-2   EDITION: METRO 
SOURCE: JOHN ARBOGAST
DATELINE:                                 LENGTH: Medium

IT'S WISE TO APPLY PESTICIDES UNDER THE RIGHT CONDITIONS

Pesticides include weed killers, insecticides, plant disease control products, plus other types of ``killers.'' The pesticide label tells how to use the product, what it will control, and where or on what plant(s) the product is intended to be used.

Before applying pesticides, be aware that weather conditions plus the time of day of application influence the application itself and the effectiveness.

The goal should be to make applications under optimum conditions, since that should result in greater control with a minimum amount of product. Application under adverse conditions might require higher rates or multiple treatments, thereby increasing the pesticide load in our environment.

Wind can cause spray droplets to drift to adjacent areas that are not meant to be treated. For herbicides, spray drift can result in uneven weed control as well as the potential for injury to non-target plants. For the homeowner, risk of injury to non-target plants from spray drift is greatest for the post-emergence lawn broadleaf weedkillers, such as 2,4-D; and for the non-selective herbicide glyphosate, which is sold as Roundup and Kleenup. One solution to this problem is to simply avoid herbicide applications under windy conditions.

Boxwood concerns

Recently, in the Roanoke area, owners of English boxwoods have been alarmed by the reddening of the foliage color and eventual death of certain branches. Boxwood owners who have called the Roanoke City Extension Office have said the red leaves have been there for months, maybe even years, which does not fit the diagnosis of boxwood winter injury.

The two likely causes of red leaves and dying branches on English boxwoods would be something adverse in the boxwoods' immediate environment, which could even include lack of care, or an incurable disease known as ``English boxwood decline.''

Noting when the symptoms were first noticed, whether there are scattered branches or color change overall, and where it occurs, on the outer shell of foliage only versus all over can help to arrive at an ``eyeball diagnosis.''

The disease ``English boxwood decline,'' for example, shows up in scattered areas or on individual twigs while other parts of the same plant may appear OK. The best ultimate diagnosis can come from root, soil and branch samples sent to the Plant Disease Clinic at Virginia Tech through your local Extension Office.

Q: We have a border of Leyland cypress trees that are around 5 feet tall and have a beautiful shape. Should we shear these up the sides the same as we do white pines? Also, would it damage the shape to cut the top? C.S.G., Moneta

A: The decision to shear the sides of Leyland cypresses depends on the owners' preference and space (width) available to the trees. This fast-growing evergreen stays rather narrow on its own, but could be sheared annually in the spring. A small amount of top growth could be removed from the central leader (main trunk) without causing permanent damage when a Leyland Cypress is young.

Send short questions about your lawn, garden, plants, or insects to Dear John, c/o the Roanoke Times & World-News, P. O. Box 2491, Roanoke, Va. 24010-2491. We need your mail, but this column can't reply to all letters. Those of wide appeal will be answered each week. Personal replies cannot be given. PLEASE DON'T SEND STAMPS, STAMPED ENVELOPES, SAMPLES, OR PICTURES.