It wasn't that long ago that someone who had aphids on their roses might grab some insect spray and let them have it, but we've learned that the casual application of deadly pesticides, herbicides and fungicides is not a good idea for the environment, the plants and ourselves.
Master Gardener Doug Freier talked about all the steps we need to take before picking up a spray gun. Here are his tips for knowing what to and what not to spray.
Identifying your problem is crucial, Freier says. Ask yourself these questions: Is the problem caused by insects? Is the whole plant affected or just a portion? Is this the right plant planted in the wrong place? Are your gardening techniques suspect? Was the damage caused by something other than a insect, such as an animal or overaggressive use of a weed whacker?
Prevention is worth a lot When selecting plants, choose varieties that are resistant to certain diseases. Make sure that you choose the right plant for the location. Trying to grow a sun-loving plant in deep shade dooms the plant to a slow death, making it susceptible to insect infestations and disease. Be sure to take good care of the plant, watering it properly and pruning at appropriate times. Failing to do so makes the plant less vigorous and sends out signals to insects that the plant is ripe for the taking. Learn to live with some bugs. Decide how much you are willing to tolerate. A few aphids may be preferable to spraying a chemical that will kill the aphids as well as beneficial insects.
Preparing for chemical warfare
Even the best gardeners do battle with insects, fungi and disease. Using chemicals should always be the last option, but sometimes chemicals are the best choice. When deciding what chemical to use, select the least lethal one available. It will get rid of the bugs, but it might take a little longer. Read the label before using. By law, the label contains information about what's in the spray as well as the dangers of misuse. Don't consider the instructions on the label as "just guidelines." If the instructions say to spray at a certain time, and a specific temperature range, or warns against overuse, believe it. Misusing sprays by applying too much or in the wrong conditions can waste your money, endanger your health and harm the plant. Always wear protective gear, usually rubber gloves, rubber boots, long-sleeved shirt and pants. Even if you think the product is completely safe, it may contain ingredients that can damage your eyes, harm you skin or irritate your lungs. Buy quality equipment. Using chemicals is much too serious a thing to cut corners. Keep your equipment clean and in working condition. Always test it before using. Don't dump left over chemicals down the gutter or drain. Consult the label for tips on disposal. Keep a log of what you sprayed, when you sprayed it and how well it worked for you.
About Our Garden
Free gardening classes are offered 10-11 a.m. on Wednesdays at the garden, Wiget Lane and Shadelands Drive in Walnut Creek. Master Gardeners are available to answer questions at the Help Desk; plants, seeds and worm compost also are available for sale.
Join us at Our Garden 10 a.m. to 3 p.m. Sept. 7 for a day of classes, demonstrations and plant sales at the Contra Costa Master Gardeners Sustainability Fair. Learn about starting your winter garden, double-digging, fruit tree pruning and much more. Tour the garden and buy winter plant seedlings. Admission to the fair is free.
Next time: Our Garden is closed Sept. 4 for the Labor Day holiday, but join us on Sept. 11 for our annual tomato tasting. Sample our tomatoes and vote on your favorites, which then will be featured in next year's tomato seedling sale.