THE 3 GARDEN PESTS I DISLIKE THE MOST

by Sue McDavid

U.C. Cooperative Extension, El Dorado County Master Gardeners

Spring is a favorite season for many people and especially for gardeners, but it's also the time of year when pesky critters seem to be everywhere. Just when you want to go outside and enjoy all the new plant growth and flowers, pests are busy devouring everything in their path. As Master Gardeners, we get lots of calls to our hotline this time of year with questions about how to get rid of these unwanted visitors, and I have found most people agree with me about their dislike for the following:

Aphids: If you have roses in your garden, you also will probably have aphids at one time or another, but they affect other plants as well. These are tiny, pear-shaped, sucking pests that come in many colors including black, green and red, and mass on new growth and flower buds. Aphids rarely kill a plant, but are unsightly and cause leaf curling as well as excrete a sticky substance called honeydew that may turn black if infected with sooty mold fungus. Ants love honeydew and will "herd" aphids for just this reason, so if you can control the ant population, you can also control aphids. Spraying your plants with water from a garden hose is another excellent control method, as is using insecticidal soap, but both will have to be done periodically. Usually aphids are only a problem for a few weeks in spring because the hot days of summer will kill most of them off. Beneficials such as ladybugs eat aphids, so I would discourage the use of synthetic pesticides as these will kill the good guys too.

Earwigs: Look for irregular holes in leaves of mature plants or entire seedlings chewed off. Earwigs hide in dark places during the day, so the best time to see if they are active is to go out after dark with a flashlight and look at your plants. One control method is to keep your garden clean of debris where earwigs hide. Unfortunately, many mulches, such as bark chips, make excellent hiding places. I wouldn't recommend getting rid of the mulch, so my favorite way of decreasing the earwig population is to place rolled newspaper or short (6" or so) lengths of garden hose around my garden. The earwigs will hide in these once it's light and I shake them out into a bucket of soapy water each morning. You won't get rid of every earwig using this technique, but you will see less of them over time. Chemical insecticides should be used only as a last resort; many of these also kill beneficial insects and you will end up with worse problems than when you started. Always read the label carefully if you do use insecticides and follow directions on the label to the letter.

Slugs and Snails: Everyone knows when these pesky critters are around – the slime trails they leave are unmistakable, as well as seedlings and leaves being completely consumed. Like earwigs, slugs and snails hide during the day in moist, dark places, such as under boards left lying around, so cleaning up debris in your garden is a good control method. Copper barriers can also be effective in controlling these pests since it is thought the copper gives off an electric "shock" which discourages movement over them. However, my favorite way of getting rid of these pests is to go out early in the morning with a bucket of soapy water and a pair of old tweezers I keep for just such a job, and any slugs or snails I find are dispatched into my bucket; you can also do this at night using a flashlight. Baits can also provide control, but use those containing iron phosphate, which is biodegradable in soil and not harmful to pets (unlike baits containing metaldehyde which should be avoided). Again, always read the label and follow the directions precisely.