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Controlling Garden Pests Year-round

Careful attention to all garden pests, including diseases, insects and weeds, is vital for gardening success. Instead of controlling them separately, consider using integrated pest management (IPM) to control these pests in a more effective, sustainable manner. Here are our expert recommendations for healthier plants, better yields and less stress for you, the grower, all year long. 

January

Plan preventative strategies to manage pests in your garden, including a rotation plan and any row covers you will use based on the previous year’s records.

Disease Control

Ornamentals: Cover boxwoods and other evergreens with burlap to prevent winter dry-out.

Fruit Trees: Prune fire blight-infected limbs from apple and pear trees, and apply copper.

February

Disease Control

Vegetables: If you are keeping your own seeds, treat them with hot water or a sodium hypochlorite solution to manage seedborne diseases.

Ornamentals: Water evergreens during ground’s transient thawing to keep plants hydrated and prevent drying out.

Weed and Insect Control

Vegetables: If not already established, frost seed legume cover crops, like red cover or hairy vetch.

March

Disease Control

Vegetables and Herbs: Buy disease-free seeds, treated seeds or disease-resistant varieties. Plant mustard cover crop (Braco White Mustard) before vegetables (except cruciferous).

Weed Control

Vegetables and Herbs: Conduct primary tillage after soil has thawed and let it fallow. Kill cover crop by tillage or herbicide.

Insect Control

Herbs: Monitor existing oregano for aphids and spider mites.

Ornamentals: Remove and destroy any bagworm cases from evergreens. Apply dormant oil on ornamental trees infested with scale insects.

April

Disease Control

Vegetables and Herbs: If rotation is not an option and soil-borne disease is prevalent, fumigate soil with Vapam (metham sodium) or plant mustard cover crop.

Greenhouses and High Tunnels: Check to see if the ventilation and exhaust systems are working properly to avoid environmental injuries to seedlings.

Weed Control

Herbs: Establish herb gardens in soils free of perennial weeds.

Insect Control

Vegetables: Watch for slugs and snails if planting early and remove debris from new plantings. Plant a trap crop earlier than main vegetables to pull Colorado potato beetle and flea beetles away from potatoes and cruciferous vegetables.

Herbs: Monitor cilantro for caterpillars.

Ornamentals and Fruit Trees: Watch for eastern tent caterpillar.

May

Disease Control

Vegetables: Avoid seeding in highly moist soil and arrange proper drainage to reduce damping off or foot rot. Remove dead and dying leaves from strawberries and other overwintered crops to reduce incidence of gray mold.

Weed Control

Vegetables: Till after weed seedlings have emerged and apply mulch prior to weed germination. Landscape fabric may be installed for perennial herbs. Prepare a stale seedbed with primary tillage.

Insect Control

Herbs: Monitor thyme for spider mites.

Vegetables: Monitor for asparagus beetles, cucumber beetles (all melons, cucumbers, squash), flea beetles (cabbage, kale, tomatoes, potatoes) and Colorado potato beetle eggs and larvae (potatoes). Use a floating row cover to keep these pests off your plants until flowering. Larger pests can be controlled by hand picking and others (Colorado potato beetles, flea beetles) by killing your trap crop.

June

Disease Control

Vegetables and Herbs: Use drip or trickle irrigation, rather than overhead sprinklers, to reduce the spread of foliar diseases. Mulch and remove lower tomato leaves to reduce Septoria leaf spot and early blight infections.

Weed Control

Remove young and actively growing weeds with a hoe or by hand.

Vegetables: Control weeds that may serve as alternate hosts for insects of vegetable crops.

Herbs: If unable to remove by hand, use clopyralid to control broadleaf weeds as well as mint and spearmint.

Insect Control

Herbs and Ornamentals: Monitor sweet basil and roses for Japanese beetles. Control by hand removal or appropriately labeled insecticides.

Vegetables: Continue to watch for asparagus beetles, cucumber beetles (all melons, cucumbers, squash), cabbage worms (cabbage, kale, broccoli) and flea beetles (cabbage, kale, tomatoes, potatoes). Monitor vegetable leaves for honeydew and other signs of aphid or whiteflies.

Fruit Trees: Watch for plum curculio damage on developing fruit, and remove all fallen fruit promptly.

July

Disease Control

Vegetables: Remove leaves showing virus infection, bacterial infection or typical fungal leaf spot.

Herbs: Monitor cilantro, tarragon and basil for downy mildew.

Weed Control

Keep the garden’s outer edge free of weeds. Cut back flowering weeds and burn seeds of invasive weeds.

Insect Control

Herbs: Monitor parsley for caterpillars.

Fruit Trees and Shrubs: Begin monitoring for spotted wing drosophila using cider vinegar traps. Start watching for brown marmorated stink bugs

Vegetables: Watch for tobacco hornworm on tomatoes and peppers. Keep ones with white cocoons (will have parasitoid wasps emerging). Continue to monitor leaves for honeydew and other signs of aphid or whiteflies. Watch for corn earworm in developing sweet corn ears.

Ornamentals: Watch for fall webworm and mimosa webworm.

August

Disease Control

Vegetables: Watch for cucurbit downy mildew and late blight on tomatoes and potatoes. Minimize overhead irrigation and apply azoxystrobin fungicide, if necessary.

Vegetables and Fruit Trees: Prune overgrown canopies to facilitate quick drying and sunlight penetration, or use a trellis.

Weed Control

Dig up entire perennial weeds root systems to destroy them.

Insect Control

Herbs: Monitor rosemary for aphids and spider mites. Apply appropriate control measures.

Vegetables: Watch for cabbage worms and their damage (early to mid-August).

Ornamentals: Continue to watch for fall webworm and mimosa webworm.

September

Disease Control

If you are saving seeds, treat them with hot water or bleach to manage seedborne diseases.

Herbs: Monitor for rust pustules on mint leaves.

Weed Control

Carefully apply glyphosate to emerged perennial weeds. Be sure to avoid contact with herbs.

Insect Control

Fruit Trees: Remove fallen fruit.

Weed and Insect Control

Vegetables: After harvest, plant a cover crop to suppress weeds and promote beneficial insects. Consider including rye grass or another small grain as your grass, rapeseed to support pollinators, and red cover or hairy vetch to fix nitrogen for your soil. Most grasses and legumes you choose must be planted by mid-September to provide cover before winter.

October

Disease Control

Remove infected produce or plant debris, or deep plow to enhance their degradation to minimize source for future infection.

Insect Control

Fruit Trees: Continue to remove fallen fruit.

Weed and Insect Control

Vegetables: If harvesting in October, plant a winter rye cover crop.

November

Disease Control

Mow fall mustard cover crop and cover with plastic mulch. Review the diseases that occurred during the season and develop a rotation plan. Explore availability of disease-resistant varieties.

December

Disease Control

Minimize humidity inside the greenhouse or high tunnel by using a high-capacity exhaust fan. Prune diseased twigs and burn them to reduce the source of infection on next year’s growth.