Some plants are friends; others hate each other. Such is the premise behind companion planting—the practice of growing specific crops in close proximity so that they may complement one another. Although its scientific legitimacy is up in the air, some studies have shown that many plants have specific compounds that repel pests and attract beneficial insects. Alliums (like the onion in bloom pictured here) are traditionally planted to repel whiteflies and aphids from the garden.
For centuries, gardeners and farmers have adhered to the idea of grouping kitchen gardens according to traditional “companion plant” pairings. If you want to experiment with companion planting, try the following combinations for a lovely, healthy, historic garden.
SUMMER SAVORY & BEANS. Garden to table is easy when this pair is planted together, since you may want to serve flatulence-fighting summer savory with beans.
OREGANO, THYME & SWEET ALYSSUM. This trio will attract beneficial insects.
RED CLOVER, ALFALFA & RYE. Suppresses weeds and pests while aiding nitrogen fixation in soil.
ONIONS & SALAD GREENS. The quick-growing salad greens will be harvested by the time the onions need the growing space.
BASIL & TOMATOES. This tasty combo is said to enhance tomatoes’ flavor.
Some herbs are friends to the garden in general. Growing these herbal superstars can benefit neighboring plants in your garden this spring.
FENNEL is traditionally recommended for attracting beneficial bugs and deterring pests. This great delicacy will attract swallowtail butterflies. If you see boldly striped caterpillars munching your fennel, just enjoy the show because soon you’ll have lovely butterflies in your garden, too.
DILL is often used to trap tomato hornworms.
BORAGE is known for effective pest control.
LEEKS traditionally serve as a garden border to keep out animals.
YARROW is said to increase the production of plants’ essential oils.
TANSY drives away ants.
A Word of Caution
Companion planting produces variable and subtle effects, especially compared to techniques like fertilization and pesticide application. But aspects of companion planting are scientifically legitimate: trap-cropping to repel pests (like planting alliums, fennel, dill, etc.), small-space combinations (for example, the “Traditional Planting” ideas at right), planting cover crops to suppress weeds and add nitrogen to the soil (such as red clover, alfalfa and rye). Some pairings only work well with specific varieties, so it may take several seasons to find a plan that works for your garden. Pay attention to where insects and birds tend to gather and keep a journal to track your observations. Talk to gardener friends to sift through what works in your area, and experiment for yourself.
To increase vegetable yield through efficient use of soil nutrients and a natural trellis, use the Native American “Three Sisters” combination of squash, beans and corn.
If you have a small garden, Chinese intercropping methods suggest double rows of garlic with a single row of spinach in between to maximize the use of space and to deter pests.
Lauren Holt is an intern and Gina DeBacker is assistant editor at The Herb Companion.