If, however, the garden world’s first responders don’t take care of the task, it’s time to intervene in as nonintrusive a way as possible, starting with nonchemical methods that keep pest populations down. Several larger pests can be simply picked off by hand, particularly when they first arrive. Bug sprays and powders, even organic ones, should be used sparingly, applied only to affected plants in the evening when the pollinators are done for the day, and never sprayed directly on open or ready-to-open flowers.
Pull On the Garden Gloves
Being a great gardener is not for the squeamish, particularly when it comes to slugs, hornworms, and cabbage loopers (cabbage worms). Go into the garden around 10 p.m. to look for them.For slugs, pick them up with an old spoon, and drop them into a container of soapy water to kill them. Three or four nights should be enough to reduce potential damage. For faster results, put stale beer in a bowl dug into the soil (so they can slither right in). They will fall in and drown. Sawdust, garden lime, or diatomaceous earth will create a handy barrier around plants but must be replaced after every rain.
Big, green, and ugly tomato hornworms are often camouflaged by the plant’s leaves. Use a flashlight to make them somewhat luminescent and easier to spot. But if the hornworm has tiny white cocoons covering its body, leave it be; these contain beneficial parasitic wasp babies that will soon feast on the hornworm.
Dill planted next to tomatoes will work as a trap crop, so you can simply pick the hornworms off the dill. Or, if the worms are tiny (less than a half-inch), spray them with the beneficial bacteria Bacillus thuringiensis (Bt).
Bad Beetles
If you see holes chewed in plants leaves, it’s the first sign of asparagus beetles, cucumber beetles, Colorado potato beetles, Mexican bean beetles, flea beetles, squash bugs, or the dreaded Japanese beetles. They also can feed on roots and ultimately kill plants.The first step is to pick off as many as possible. The adults are usually easy to spot, with their colorful oval or round hard-shell bodies, small heads, six legs, and a pair of antennae.
Shake the plants to make the bugs fall off, then drop them into a container of soapy water. Repeat every few days as needed. Insecticidal soaps like Dr. Bronner’s can be sprayed directly on the bugs to kill them without harming the plants. Be sure not to spray it on any beneficial bugs nearby. Pheromone beetle traps work well to catch males and decimate their reproductive cycle.
Aphids, Whiteflies, and Spider Mites
Tiny green, white, yellow, red, brown, black, and mottled aphids may arrive in a garden all on their own, or ants might bring them in to be “farmed.” As aphids suck the sap from plants, they secrete a honeydew-like substance that ants love. In fact, the ants stroke the aphids’ abdomens as a form of milking them, and they protect them from their other natural predators.
A strong blast of a hose will knock aphids loose, damaging their fragile exoskeleton in the process. They can also be hand-removed or sprayed with insecticidal soap. As they are known to transmit plant diseases, fully infested plants should be destroyed.
Even smaller white-winged whiteflies arrive en masse to infect plants with diseases, which results in a sooty mold. A vigorous blast with the hose will usually get rid of them. They reproduce (lay eggs) rapidly, so hosing daily may be necessary. For stubborn situations, use an insecticidal soap.
While most spiders in the garden are good guys happily dining on pests, spider mites literally suck the life out of plants, and have been known to use their teeth on humans, too. Spray the undersides of leaves with a hose or wipe them down with a solution of insecticidal soap in water to eliminate these pests.
