They emerge from the soil, crawl out of the leaf litter, and descend from the sky. Garden pests – sap-sucking insects, leaf munching insects, and plant parasitizing insects – kill plants and destroy crops. Gardeners have fought an epic battle against these enemies of the garden for centuries.
Controlling these pests requires a diverse arsenal of organic pesticides, beneficial insects, and a variety of other methods.
Carefully monitoring, handpicking insects, and using insect traps are the gardener’s first line of defense. These methods, however, are not as effective when you are dealing with a severe infestation of insect pests.
Oils and soaps can help control soft-bodied insects – aphids, mites, whiteflies, and worms. Two applications of insecticidal soap, a week apart, should be sufficient to control an infestation. A strong spray of water will knock most insects off of the plant. Then saturate the foliage with the soap.
To protect your crops from cabbage loopers, cabbageworms, and corn borers, dust plants with BT (Bacillus thuringiensis), a biological pesticide that comes in a powder form. Spinosad, a combination of two natural bacteria, can also control these pests and more. Use it to knock down armyworms, fire ants, and flea beetles.
Diatomaceous earth is a powdered form of fossilized algae. The abrasive and dehydrating properties of this biological pesticide provide effective control of slugs and snails.
Use insecticides and other pesticides only as a last resort and very sparingly, spraying when there is little or no wind during the middle of the day when insect activity is at a minimum. But remember, even organic pesticides have the potential to cause harm if used improperly. If using a knockdown spray, beneficial insects will inevitably be collateral damage. Those that survive will leave your garden, but the damaging bugs will quickly return in force.
“If we throw Mother Nature out the window, she comes back through the door with a pitchfork.” – Masanobu Fukuoka.
Attracting Beneficial Insects
In a balanced natural ecosystem, pest infestations are rare. Any population explosion of pest insects quickly becomes a buffet for beneficial insects, lizards, and other amphibians.
The ladybug is only one among thousands of beneficial insects that prey on garden pests. Beloved by gardeners the world over, the ladybug is a ferocious guardian of the garden. Dressed in formidable armor – brightly colored shield on its back, poisonous deposits in the knee joints, and toxic blood – she’s a killer. They have a voracious appetite – a ladybug can eat up to 5,000 insects in its lifetime. Aphids, mealy bugs, mites, and thrips are favorite prey. Once attracted to a garden, the ladybug is either eating or reproducing. Her promiscuity and gluttony are the gardener’s boon.
The praying mantis is at the top of the insect food chain, and their presence is an indicator of a very healthy environment. This ambush predator grabs its prey with lightning quick speed.
Parasitic wasp species number in the thousands, perhaps one or more species for every pest insect. These wasps don’t eat insects but insert their eggs into the bodies of the pest insect. The wasp’s larvae eat the insect host from the inside out.
To attract these garden warriors, plant a wide variety of old-fashioned, open-pollinated flowers such as aster, butterfly weed, spiderwort, salvia, clover, Joe-pye weed, and black-eyed Susan. Allow herbs to flower and resist the urge to use pesticides.
Other Methods of Pest Control
Planting the same crop in the same location year after year allows populations of pests that attack that crop to build up. The practice of rotating crops can mitigate these population build-ups. Crops should not be grown in the same planting beds more often than once every four years.
Physical barriers, such as crop covers can help prevent many insect pests, including the squash vine borer. Rigid collars around the stems of seedling keep cutworms at bay.
Ducks, Guinea hens, and chickens can be a gardener’s best friend. Grasshoppers, beetles, cabbageworms, fire ants, grubs, and many other insects don’t stand a chance against the voracious appetites of poultry. Allow ducks and guinea hens to free range, but keep chickens out of the garden until fall. Chickens can damage crops and plants, particularly seedlings, but they are heroes at rooting out overwintering grasshopper eggs.