Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, June 25, 1995 TAG: 9506270009
SECTION: HOMES PAGE: B-2 EDITION: METRO
SOURCE: JOHN ARBOGAST
DATELINE: LENGTH: Medium
To do so, gardeners need to avoid plants that are known for insect problems and to select disease-resistant varieties whenever possible. Also critical is the care the garden gets.
Cultural techniques include: watering at a time that allows plants to dry before night; mulching to reduce weed growth as well as to increase retention of soil moisture; practicing sanitation, which includes promptly removing dead or rotten plants and/or fruits to reduce the attraction of insects and disease organisms to your garden; and harvesting produce just as soon as it ripens, again to avoid attracting problems from overripe vegetables.
A major component of reducing chemical use in the garden as well as just growing a productive garden is to frequently observe the plants and look for problems, which could be insects or diseases. When problems occur, it's important to discover them early and control them right away, either by removal of pests or their eggs, elimination of diseased parts and applying controls where appropriate before things get out of hand.
Actually, problem-control requires planning ahead, particularly when thinking about using beneficial insects to control the bad insects. It seems that more information and products are available on so-called ``organic'' controls for insects compared to disease controls.
Eric Day, extension entomologist at Virginia Tech, wrote that ``Botanical insecticides are derived from various plant parts and are commonly used in organic control situations. It is important to read the label [for these products] and follow all precautions regarding protective clothing, mixing and labeled plants. Just because it is derived from plants doesn't mean that safety can be disregarded. Biological control is in two major forms: (a.) microbial, which is a formulation containing a microorganism, such as Bacillus thuringiensis (commonly known as B.T.), or (b.) the release of predatory insects or mites, such as lady beetles. A current list of suppliers of biological control agents can be obtained from: The IPM Practitioner, Box 7414, Berkeley, Calif. 94707. [Gardeners must] use caution with insecticides when a release of predators is planned [so your sprays don't kill the good guys you'll soon release].''
Q: We have a pink and a white dogwood planted opposite each other with a walk in between. The pink dogwood blossoms have been ``fading'' each year; this year they looked more white than pink. Could this be cross pollination from bees? Also, a chain was secured around this pink dogwood to help hold a bulldozer on a steep hill. The tree shook vigorously. Did this likely hurt the tree? Other than examining the bark for mechanical injury and checking the base of the dogwood for loosened soil, do you have other suggestions? What is your best guess as to whether this tree has suffered permanent damage?
A: The fading is likely a natural evolution for your particular tree. Others have asked about the fading of pink dogwoods over the years, so this happens but is not predictable, in my opinion. Dogwood-flower color change would not be the result of cross pollination by bees.
Yes, the chain attached to the dogwood to hold the bulldozer likely harmed the tree. Your suggestions for examining the bark and looking for loosened soil are great. Trim off any loose bark you find. Give the dogwood a good soaking once per week during the entire growing season. A dogwood with a wounded trunk is more attractive to the dogwood borer pest.
Except for immediate results of broken bark and wounds, only time will tell about the life and vigor of the injured tree.
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.
by CNB