Comprehensive Guide to Common Garden Pest Control

Nothing ruins a garden day like a pest outbreak. Control depends on the invader. Here's a rundown of common pests and management strategies.

Aphids

Appearance: Pear-shaped, soft-bodied, winged or wingless; some have a white cottony coating.
Damage: Cluster on stem tips, suck sap, distort growth, spread viruses, and excrete honeydew that attracts ants.
Control: Ladybugs and other beneficials usually keep them in check. A strong water spray knocks them off. Insecticidal soap works well.

Caterpillars & Worms

Appearance: Larvae of moths and butterflies.
Damage: Chew holes in leaves and stems.
Control: Birds, parasitic wasps (look for white eggs on caterpillars), row covers (remove for pollination), Bt (Bacillus thuringiensis), or pyrethrin (botanical insecticide).

Earwigs

Appearance: 3/4 inch, pincers at rear, nocturnal.
Damage: Holes in leaves, stems, flowers, fruit.
Control: Cardboard traps overnight, pesticides, or bait pellets.

Japanese Beetles

Appearance: Metallic blue-green, 1/2 inch, coppery wings.
Damage: Skeletonize leaves and flowers; grubs eat grass roots.
Control: Hand-pick into soapy water. Apply beneficial nematodes (Heterorhabditis bacteriophora) to lawns in spring. Spray neem, malathion, or carbaryl for adults. Traps work but place far from vulnerable plants.

Mealybugs

Appearance: Small, cottony, sap-sucking.
Damage: Secrete honeydew leading to sooty mold and ants.
Control: Plant sweet alyssum and Scabiosa to attract predators. Insecticidal soap, summer oil, neem, or carbaryl sprays help.

Scale Insects

Appearance: Mobile crawlers settle and form hard, oval shells on bark.
Damage: Suck plant fluids, causing yellowing, stunting, dieback.
Control: Dormant oil in late winter. Neem, carbaryl, or horticultural oil in growing season.

Slugs & Snails

Appearance: Slimy, black/brown slugs with antennae; circular snails.
Damage: Rasping holes in leaves/flowers at night; leave slime trails.
Control: Clean debris, hand-pick at dusk. Wood ashes or diatomaceous earth dehydrate them. Beer traps drown them. Iron phosphate baits are safe for birds/pets. Copper barriers shock them.

Tent Caterpillars

Appearance: Various species; eastern tent caterpillar has white-striped back and blue spots; fall webworm is small and fuzzy.
Damage: Webs spanning branches; can defoliate trees in severe cases.
Control: Trunk barriers to stop ground migration. Birds and wasps eat them. Remove/burn reachable nests. Spray Btk (Bacillus thuringiensis var. kurstaki) on small larvae. Open high nests and spray pyrethrum or pyrethrin. Ornamental trees: acephate, carbaryl, or malathion. Dormant oil on eggs in winter.

Note: Healthy plants in proper conditions resist pests better. Always read insecticide labels for correct use.