KENNEWICK -- Last week, we talked about "midnight marauders," garden pests that attack plants at night. This includes slugs, earwigs and root weevils.
Today, let's talk about how to manage them and limit their damage.
Many of these nocturnal pests hide in nearby weeds or under plant debris during the day, so the first step is to tidy up the garden. Get rid of hiding places in and near the garden, such as rocks, boards, clumps of dirts and plant litter. Remove or mow tall grasses and rogue out weeds.
Welcome birds, spiders, ground beetles, garter snakes and frogs to your garden. These natural predators can help keep these pests in check. Earwigs and slugs prefer damp conditions. By using drip irrigation in your garden and drying out the soil surface, both can both be discouraged.
If these measures fail to keep these pests in check, trapping is a non-chemical control approach to take before using pesticides as a last resort.
Traps are easily created with deep saucers, pie pans or cans sunk in the ground so the edge of the container is level with the soil. Beer is added to attract slugs within a few feet or so from the trap. The slugs crawl into the trap and and drown. Remove dead slugs daily and refresh with new beer every few days.
Slugs can also be trapped by placing boards or wet, unrolled sections of newspaper down on the soil near damaged plants. Each morning, lift them up and handpick any slugs hiding underneath.
When earwigs have been a significant problem in your garden in past years, frequent shallow cultivation of the soil, especially early in the spring, will disrupt nests and destroy eggs.
Earwigs can be trapped in shallow tuna or cat food cans. Place the clean cans in the garden, and fill them with about a half-inch of vegetable oil. The earwigs climb in and drown. Make sure the level of the oil is at least 1-inch below the edge of the container. When full of earwigs, empty and renew the trap. Some gardeners say adding a few drops of molasses on top of the oil makes the traps more attractive to the earwigs.
Another earwig trap consists of loosely rolling up a moistened section of newspaper and securing it with rubber bands. The roll will trap more earwigs if baited with wheat germ or wheat bran before rolling. In the evening, place the moistened rolls out in the garden near damaged plants. In the morning, collect the rolls, seal them in a plastic bag and dispose of them in the garbage. Repeat this nightly for several weeks.
A simple method for trapping root weevils is to place a sheet beneath each of the damaged plants in the evening. Go out after dark with a flashlight, and shake the affected plants. The feeding weevils will drop to the sheet. Collect the weevils, and drop them in some soapy water. Do this nightly until you are catching few to no weevils.
There are a number of pesticide products available for control of slugs, earwigs and cutworms in the garden. If you're using the product in a vegetable garden, make sure it's recommended for use around food crops. Slug baits containing iron phosphate are effective and less toxic than other baits. Whichever products you select, be sure to read label directions.
Note that baits can be attractive to pets. Follow all label precautions to avoid poisoning pets or bees.
* Marianne C. Ophardt is a horticulturist for Washington State University Benton County Extension.