Go Herbal to Control Garden Pests
McIntyre, author of The Complete Woman's Herbal (Gaia, 1994), says some herbs are natural insecticides and should be made an integral part of any garden. If you're growing beans, lettuce, potatoes or tomatoes, plant marigold nearby, because it deters harmful butterflies, slugs and potato eelworm.
Nasturtiums are ideal for guarding peas and tomatoes, she says, while garlic fends off the slugs and flies that can bug peas, carrots, tomatoes and strawberries. Also of value in the average garden are peppermint, thyme, chives, lavender, rosemary, dill and sage.