According to the Environmental Protection Agency, pesticides have been linked to cancer, nerve damage, birth defects and other medical problems. Fortunately, there are many natural ways to control or eliminate common garden pests such as aphids, white flies and spider mites without resorting to dangerous pesticides.
Three of the best methods of natural pest control are incorporating pest-repellent plants into your garden, encouraging pest-reducing insects such as ladybugs to visit your plants, and applying home-brewed non-toxic pesticides.
Plants that repel pests
There are plants that you can add to your garden that repel pests. These include:
- Basil – asparagus beetles, tomato heartworms and thrips
- Green Bean – Colorado potato beetles
- Nasturtium – Colorado potato beetles and squash bugs
- Tomato – asparagus beetles
- Wormwood – slugs
- Rue – aphids, cats, dogs, Japanese beetles, onion maggots, slugs and snails
- Anise – aphids, snails and slugs
- Borage – cabbage worms and tomato heart worms
- Sage – cabbage loopers, carrot flies, flea beetles, imported cabbage worms and tomato heart worms
- Thyme – cabbage loopers and white flies
- Radish – cowpea curculio, cucumber beetles, harlequin bugs, Mexican bean leaf beetles, squash bugs and stink bugs
- Garlic – aphids, cowpea curculio, flea beetles, Japanese beetles, Mexican been leaf beetles, root maggots, spider mites and squash vine borers
- Onion – bean leaf beetle, cabbage loopers, carrot flies, flea beetles, harlequin bugs, Mexican bean leaf beetles, mice, rabbits, spider mites and squash vine borers
- Potato – bean leaf beetles
- Turnip – bean leaf beetles and harlequin bugs
- Oleander – codling moths
- Catnip – aphids, corn earworms, cucumber beetles, flea beetles, Japanese beetles, squash bugs and mice
- Marigold – aphids, corn earworms, leaf hoppers, Mexican bean leaf beetles, rabbits, squash bugs, thrips and tomato heartworms
- Hyssop – imported cabbage worms
- Oregano – cabbage butterflies and cucumber beetles
- Rosemary – imported cabbage worms and slugs
- Dill – aphids, cabbage moths and spider mites
- Lavender – mice, mosquitoes, moths, rabbits and ticks
- Fennel – aphids, slugs, snails and spider mites
- Pennyroyal – ants
- Mint – ants, aphids, cucumber beetles, flea beetles, imported cabbage worms, rodents, squash bugs and white flies
- Tansy – ants, cucumber beetles, Japanese beetles and squash bugs
- Coriander/Cilantro – aphids, Colorado potato beetles and spider mites
- Horseradish – potato beetles
- Geranium – Japanese beetles, leaf hoppers
- Butterfly (white) Sage – asparagus beetles
- Larkspur – Japanese beetles
- Chives – aphids, Japanese beetles and spider mites
- Cloves – cowpea curculio, spider mites and squash vine borers
- Lettuce – carrot flies
- Petunia – leafhoppers, Mexican bean leaf beetles and squash bugs
- Parsley – asparagus beetles and carrot flies
There are plants that can protect other plants from pests and disease and improve the flavour of certain food plants. Some examples include:
- Basil planted near tomatoes improves flavour and protects against a variety of pests.
- Oregano planted near cabbage, broccoli, cauliflower, cucumber or grape vine repels pests that attack these plants
- Garlic helps prevent disease in rose canes and raspberry
- Borage repels pests that attack tomatoes and attracts pollinators to squash, tomatoes and strawberries.
- Horseradish planted at the corners of a potato patch with beans also planted nearby repels potato beetles
- Chives planted near apples help to control apple scab.
- Chives planted near roses reduce the risk of “black spot” and repel aphids.
- Chives planted near tomatoes and carrots repel pests and improve the flavor of the vegetables
- Petunias repel pests that attack beans
Make your own non-toxic pest repellents and insecticidal soaps
North Carolina’s Division of Pollution Prevention and Environmental Assistance offers a number of recipes for non-toxic pesticides that you can make at home and apply to your plants with a spray bottle, including the following:
- Grind 3 large onions, 1 bunch of garlic and 3 hot peppers. Mix with water and leave overnight in a covered container. In the morning, strain through fine strainer or cheesecloth and add sufficient water to produce approximately one gallon (16 cups) of pesticide.
- Soak 10-15 diced garlic cloves in a pint (2 cups) of mineral oil for 24 hours. Strain and add to a spray bottle.
Annie B. Bond, Care2 Green Living Executive Producer, offers a recipe for all-natural insecticidal soap spray, which uses 1-2 tablespoons of a natural liquid soap such as Dr. Bronner’s Pure-Castile soap in a quart (4 cups) of water. Once this solution is mixed, it can be added to a spray bottle.
Attract beneficial predators such as Ladybugs, Praying Mantises, Dragonflies and Spiders
Another method of natural pest control is attracting ladybugs to your garden. Ladybugs are voracious consumers of aphids and other garden pests. Plants that attract ladybugs include Angelica, Caraway, Cilantro, Coreopsis, Cosmos (particularly white), Dandelions, Dill, Fennel, Geraniums, Tansy and Yarrow. Ladybugs can also be purchased from certain garden supply stores.
There are other insects that can aid in pest control, such as praying mantises and dragonflies. Spiders (which are arachnids rather than insects) are also highly beneficial.
For more gardening articles, visit the main Gardening page.
- Art Knapp Information Library. (n.d.). “Plants That Repel Pests.” ArtKnapp.com.
Bond, A.B. (30 May 1999). “Homemade Insecticidal Soap Spray.” Care2.com.
- City of Carlsbad, Public Works, Municipal Water Division. (2007). “Plants That Repel Pests.” Carlsbadca.gov.
- Environmental Protection Agency. (2007). “Pesticides and Food: Health Problems Pesticides May Cause.” EPA.gov.
- Ferragine, F. (n.d.) “12 Pest-Repelling Herbs.” CanadianLiving.com.
- Government of Yukon. (2007). “Natural Pest Control for Your Garden.”
- Hamir, A. (2008). “Luring Ladybugs Into Your Garden – Garden Pest Tip.” GardenGuides.com.
- North Carolina Division of Pollution Prevention and Environmental Assistance (DPPEA). (n.d.) “Home Brewed Pest Control.” P2pays.org.