Integrated pest management (IPM) is a decision-making framework that uses the least toxic option that solves the problem. The goal isn't to eliminate all pests — it's to keep pest damage below an acceptable threshold.
The IPM ladder — use in order:
Step 1: Prevention Most pest problems are prevented, not treated. Healthy plants in well-amended soil resist pests better than stressed plants. Row covers stop insects from reaching plants entirely. Crop rotation prevents soil-dwelling pests from finding host plants year after year.
Step 2: Monitoring Walk your garden every 2–3 days and actually look at plants. Turn over leaves, check stems. Catching problems when populations are small is 10x easier than dealing with an established infestation. Keep a simple log: what you saw, where, what stage (egg, larva, adult).
Step 3: Mechanical control Handpicking, traps, and physical barriers. For caterpillars: check under leaves and pick off by hand daily. For slugs: set beer traps (a container sunk flush with soil and filled with beer — slugs crawl in and drown). For aphids: blast with water from a hose.
Step 4: Biological control Encourage and protect natural predators. Ladybugs, lacewings, parasitic wasps, and ground beetles all eat garden pests. To attract them: plant flowers (especially umbel-shaped flowers like dill, fennel, cilantro) near vegetable beds and avoid broad-spectrum pesticides that kill beneficial insects.
Step 5: Organic sprays Neem oil disrupts insect development and has antifungal properties. Insecticidal soap kills soft-bodied insects (aphids, spider mites, whiteflies) on contact. Bacillus thuringiensis (Bt) is a soil bacterium that kills caterpillars but is harmless to other organisms. Spray in the evening to protect pollinators.
Step 6: Synthetic pesticides Last resort only. If you reach this step, use targeted products — pyrethrin is less persistent than most synthetics. Never spray during bloom when pollinators are active.
The key insight: A few aphids won't kill your tomato plant. A few caterpillar holes in a cabbage are cosmetic. The threshold for action depends on crop, pest, and growth stage. Not every pest requires treatment.