Companion Planting: Best & Worst Garden Buddies for Your Greenhouse

Basil

Asparagus, beets, borage, carrots, chamomile, onions, marigolds, oregano, peppers, tomatoes.

Borago improves the growth and taste of basil. Chamomile, chives, and oregano increase the content of essential oil in basil. Basil and marigolds together are a powerful natural pest repellent. Basil itself repels aphids, asparagus beetles, and tomato hawk moths. It also increases tomato yields, and the flowers attract pollinating insects.

Cucumber, fennel, rue, sage

Eggplant

Beans, catnip, marigolds, peas.

Catnip repels fleas, a common pest of vegetable crops. Beans and peas fix nitrogen in the soil. Marigolds repel nematodes and aphids.

Others from the nightshade family: peppers, potatoes, tomatoes, which make eggplants more susceptible to late blight.

Beets

Cabbage, garlic, kohlrabi, leeks, lettuce, onions.

Garlic improves the growth and taste of beets.

Beans and beets inhibit each other's growth.

Peas

Carrots, celery, corn, cucumbers, eggplants, lettuce, potatoes, radishes, spinach, tomatoes.

Peas combine well with many vegetables, as they increase the availability of nitrogen in the soil.

Onions can delay the growth of peas.

Zucchini

Beans, borage, corn, marigolds, nasturtium, peas, radishes, tansy.

Borago attracts pollinating insects, improves growth and taste. Nasturtium, radishes and tansy repel aphids and other pests.

Potatoes, pumpkins.

Potatoes compete for nutrients. Pumpkins, which are closely related to squash, can cross-pollinate.

Cabbage

Bush beans, beets, celery, chamomile, dill, mint, onions, oregano, rosemary, sage, savory, nasturtium.

Marigolds and aromatic herbs such as mint, rosemary, and savory repel cabbage moths. Dill, celery, garlic, mint and onion improve the taste of cabbage.

Beans, mustard, strawberries, tomatoes.

Broccoli

Basil, beets, celery, cucumber, dill, garlic, lettuce, marigolds, mint, nasturtium, onions, potatoes, radishes, rosemary, spinach, thyme.

Dill attracts predatory wasps that fight pests. Rosemary repels cabbage flies. Celery, potatoes and onions improve the taste of broccoli.

Asparagus, beans (climbing), corn, melons, peppers, pumpkin, squash, strawberries.

Potatoes

Basil, beans, cabbage, chamomile, corn, horseradish, lettuce, marigolds, parsley, peas, radishes, spinach, thyme.

Beans repel the Colorado potato beetle. Horseradish increases resistance to diseases. Many herbs, such as basil, chamomile, parsley and thyme, improve the taste of potatoes, attract beneficial insects.

Cucumbers, raspberries and tomatoes attract insects. Avoid planting near other vegetables from the nightshade family. Asparagus, carrots, fennel, onions can retard potato growth.

Beans (bush)

Beets, cabbage, carrots, catnip, celery, corn, cucumber, eggplant, marigolds, nasturtium, peas, potatoes, radishes, rosemary, zucchini.

Catnip repels flea beetles, a common pest of vegetable crops. Marigolds, nasturtiums, and rosemary repel numerous pests. The beans themselves provide the soil with nitrogen.

Onions, in particular onions and garlic, which can inhibit the growth of legumes.

Beans (climbing)

Broccoli, cabbage, carrots, catnip, celery, corn, cucumber, eggplant, marigold, nasturtium, peas, potatoes, radishes, rosemary, zucchini, strawberries, tomatoes.

Corn is used as a natural trellis, providing the beans with shade. Zucchini shades the roots and repels pests.

Beets cause stunted growth of climbing beans, but bush beans do not suffer from this. Also, poor growth of beans is caused by proximity to onions.

Dill

Cabbage, corn, cucumber, lettuce, onion.

Dill repels pests including aphids, cabbage moths, and spider mites. It also attracts beneficial insects such as bees, ladybugs, and parasitic wasps.

Cilantro, carrots, tomatoes. Dill cross-pollinates with cilantro and carrots.

Corn

Beans, cucumber, marigolds, melon, parsley, peas, potatoes, pumpkin, squash, sunflower.

Beans and peas add nitrogen to the soil. Marigolds repel pests. Corn provides shade and is a natural support for beans.

Celery, tomatoes. Tomatoes attract pests that attack corn, including tomato hawk moths and cutworms.

Carrots

Beans, onions, lettuce, chives, peas, peppers, radishes, rosemary, sage, tomatoes.

 Beans fix nitrogen in the soil. Chives improve growth and flavor. Onions, parsley, rosemary and sage repel carrot flies.

Dill and parsnips, which can delay carrot growth.

Mint

Beets, cabbage, eggplant, lettuce, peas, zucchini.

Mint is a natural pest control. It repels fleas, aphids, carrot flies, onion flies and spider mites. Mint attracts beneficial insects such as ladybugs and predatory wasps that feed on pests.

Chamomile, parsley

Cucumber

Beans, brassicas, corn, dill, lettuce, marigolds, nasturtium, peas, radishes.

Dill attracts beneficial insects that feed on pests such as the corn rootworm. Nasturtium repels aphids and beetles while improving growth and flavor. Radishes repel pests.

Aromatic herbs (except dill), potatoes, tomatoes. Cucumbers do not grow well if planted near potatoes or sage.

Peppers

Basil, beans, beets, carrots, chives, coriander, cucumber, dill, eggplant, garlic, lettuce, parsley, onions, spinach, tomato.

Basil repels aphids, spider mites and thrips, and improves the taste of peppers. Dill and coriander repel aphids and attract beneficial insects. Parsley attracts predatory wasps that feed on aphids. Alliums repel aphids, beetles, snails, and spider mites.

Brassicas, including broccoli, Brussels sprouts, cabbage, and cauliflower.

Strawberries

Beans, borage, caraway, onions, garlic, lettuce, sage, spinach, savory.

Garlic and onions repel insects. Borage attracts pollinating insects and repels strawberry pests. Caraway attracts beneficial insects such as wasps that attack strawberry pests.

Avoid planting near plants susceptible to verticillium wilt, such as eggplant, peppers, potatoes and tomatoes. Strawberries can suppress the growth of legumes, as well as broccoli and cauliflower.

Radishes

Beans, carrots, cucumber, lettuce, melon, nasturtium, peas, spinach, squash.

Nasturtium improves the growth and taste of radishes. The radish itself repels many pests of cucurbits.

Cabbage, hyssop inhibit the growth of radishes.

Rosemary

Beans, broccoli, cabbage, carrots.

The pungent aroma of rosemary repels many pests, including cabbage moth, cabbage moth, carrot fly, snails, slugs and weevils. Rosemary flowers attract pollinating insects. Rosemary enhances the flavor of sage.

Pumpkin, zucchini

Asparagus

Basil, coriander, dill, marigold, parsley, tomatoes.

Basil, marigolds, parsley and tomatoes protect against asparagus beetles. Coriander and dill repel pests such as aphids and spider mites.

Garlic, onions, potatoes

Tomatoes

Asparagus, basil, borage, carrots, celery, cucumber, garlic, lettuce, marigolds, mint, onions, parsley.

Basil improves the growth of tomatoes and repels pests. Marigolds repel pests. Plant tomatoes next to asparagus to repel the asparagus beetle.

Dill, broccoli, Brussels sprouts, cabbage, and cauliflower can stunt tomato growth. Corn attracts tomato

Onions

Beets, cabbage, carrots, chamomile, lettuce, peppers, strawberries, tomatoes.

Onions repel root crop pests, including cabbage root fly, aphids, carrot flies, and Japanese beetles.

Asparagus, beans, peas, sage. Avoid planting near other allium crops such as garlic, leeks and shallots to avoid the spread of common diseases and pests.

Garlic

Beets, broccoli, cabbage, carrots, cauliflower, dill, eggplant, kohlrabi, peppers, potatoes, spinach, tomatoes.

Garlic repels a wide range of pests, including ants, aphids, cabbage flies, Japanese beetles, onion flies, snails, and spider mites.

Garlic can stunt the growth of asparagus, beans, parsley, peas, and sage.