Your vision of harvesting and enjoying fresh produce straight from your back yard is just a few ripe tomatoes away. Don’t let a pest infestation turn that dream into a nightmare. Help keep your vegetable garden – and other planting beds – healthy and free from serious pest attack. Here’s a look at some common symptoms you may notice on your plants, as well as possible causes and remedies.
Tomato hornworms grow to near-gigantic size in a matter of a week from the time they hatch.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Japanese beetles eat the portion of the leaf between the veins, so what’s left of the foliage typically resembles Grandma’s lace doilies.
Photo Credit: ©2002 Dolezal Publishing/John M. Rickard
Symptom: Leaves are curled and twisted, often with a black, sooty appearance. Deformed or stunted blooms on new growth.
Cause: Aphids...
Remedies: Wash off light infestations with a strong stream of water. If that’s ineffective, spray with insecticidal soap or horticulture oils. (Only spray with botanical neem or pyrethrin as a last resort.)
Symptom: Green parts of leaves are chewed, removed or left in place but stripped to veins. Later, leaves become dry and skeletonized.
Cause: Beetles, including Colorado potato beetles, Japanese beetles and beetle larvae. (Hard-shelled beetles are most active in the heat of the day.)
Symptom: Seedlings cut off at ground level.
Cause: Cutworms. Look for smooth, gray-brown, wormlike moth larvae under plant debris or just below soil surface.
Symptom: Foliage is eaten and stems are scored or eaten. Black or brown droppings, 1⁄20 of an inch wide, are left on foliage. Moths and butterflies are seen resting on plants.
Cause: Various larvae and caterpillars, white cabbage moth, tomato hornworm, wormlike larvae, and/or loopers. Look at undersides of leaves and along stems for pests during midday.
Remedies: Handpick caterpillars from the center leaves of plant. Release parasitic wasps and flies, natural predators of these pests. Spray with Bacillus thuringiensis (Bt). Apply horticultural oil in summer.
Symptom: White trails on or within leaves. Papery yellow or brown blotches on foliage.
Cause: Leaf miners. Look for small, pale larvae and 1⁄6-inch, green or black, flying insects active during the day.
Remedies: Handpick larvae. Remove infested leaves. Release lady beetles – they’re natural predators. (Only spray foliage with neem oil extract solution as a last resort.)
Symptom: Stunted, discolored, spotted plants with deformed roots, sometimes bearing swollen galls. Loss of vigor.
Cause: Nematodes, microscopic wormlike creatures that live in soil and feed on plant roots.
Remedies: Release beneficial nematodes to attack the “bad guys.” Remove and destroy affected plants. Replant with unrelated species. Solarize bed for 3-4 weeks prior to replanting by covering soil with clear plastic and allowing sunlight to raise soil temperature to 140 degrees F.
Symptom: Leaves with brown or black spots. Roots and shoots may be deformed.
Cause: Plant bugs. Look for greenish-yellow or tan insects 1⁄4 an inch long.
Remedies: Handpick. Spray with insecticidal soap. (If infestation is severe, spray affected areas with pyrethrin or rotenone, but only as a last resort.)
Symptom: Brown-, silver- or white-speckled leaves; may be gummy or deformed. Blooms are deformed and fail to open.
Cause: Thrips. Shake foliage and blossoms over white paper and look for moving, winged specks. (These pests thrive in hot, dry conditions.)
Remedies: Release lady beetles. Remove and destroy infested foliage. Wash leaves with water; spray pests with insecticidal soap.
Symptom: Yellow leaves and stunted, sticky plants. When foliage is shaken, a cloud of white insects may fly up.
Cause: Whiteflies. Shake foliage and look for 1⁄20-inch, mothlike, flying insects. Inspect leaf undersides for gray or yellow, scalelike eggs.
Remedies: Catch with sticky traps. Spray with soap solution or insecticidal soap. Spray foliage with horticultural oil or neem oil extract solution. (Only spray with pyrethrin as a last resort.)
