How to Reduce Your Use of Pesticides Cultural practices Choose plants with known resistance to common problems. Biological controls Include plants near your garden that favor natural enemies of garden pests. Marigolds will repel nematodes, for instance, and ladybugs are available locally commercially for control of aphids. Many predators, parasites and pathogens of garden pests are available commercially. Bacillus thuringiensis, a naturally occurring pathogen, is available for the control of caterpillars.
Insecticidal soap is potassium salt-based and controls aphids, red spider mites and mealy bugs.