Good and Bad Plant Bedfellows - Best Plant Companions and Foes for Vegetables

The first and fundamental reason for companion planting is to increase diversity. This is independent of any other reason such as pest control and nutrients. It makes sense that if all the plants in a patch are the one species, they will be competing for exactly the same nutrients and space, vertical and horizontal. Crowding the same species together increases the risk of spreading diseases, and pests will have a field day. If instead you plant different types of plants in a scattered pattern you will develop a balanced ecosystem with diversity.

This allows maximum beneficial interplay between plants. This extends to the creation micro-climates and genuine partnerships between plants that do well with each other. It can also confuse insect pests, and even birds by creating a diversity plant odours and a range of colours and shapes which will make pests less successful and easier to control. Likewise, diseases will be less likely to spread from plant to plant of the same species if they are spaced among other plants.

Many flowers and herbs repell insect pests when planted as companions for vegetables
Many flowers and herbs repell insect pests when planted as companions for vegetables Source: Public Domain

Pest and disease control are not the only advantages of companion planting. Some plants are nitrogen-fixers, storing nitrogen captured from the air made in their root systems. This extra nitrogen can become available for other crops. Likewise these plants will not be drawing upon the limited amount of nitrogen in the soil. So planting nitrogen fixing plants like beans and peas can be beneficial when paired with plants having high fertiliser demands.

Companion plantings increases diversity and reduces vulnerability to pests and diseases
Companion plantings increases diversity and reduces vulnerability to pests and diseases Source: Public Domain

Flowering plants in vegetable garden beds also help to attract pollinators. Other plants many provide a ground cover to simply suppress weeds, or provide partial shading.

The Perfect Couple - Plant Pairing Works
The Perfect Couple - Plant Pairing Works. Source: Public Domain

Other benefit of companion plantings is to create vertical structure. One good example is planting corn with climbing beans or peas that can climb on the bean stalks. You can also plant squash, cucumber or pumpkin vines underneath. This principle of companion planting is called the "Three Sisters" and was used by Native Americans. Corn gives the beans or peas a structure to climb on. Beans lock atmospheric nitrogen in their roots helping to fertilise the soil and reducing demand for soil nitrogen needed by other plants. The spreading vines and leaves of pumpkins, cucumbers or squash create a living mulch and micro-climate that retains soil moisture and suppresses weed growth.

The 'three sisters' approach for companion planting - corn, squash and climbing bean
The 'three sisters' approach for companion planting - corn, squash and climbing beans. Source: Public Domain

Some other Benefits of Companion Planting include:

Minimizing Risk for Yields - Companion planting increases odds of good yields from your garden patch. Even if one crop fails or is badly affected by natural hardships such as weather, pests or disease, the companion plants will still give you a yield.

Physical Plant Protection - Companion plants can offer a more delicate plant shelter from wind or shade from hot sun. Growing plants beside another more vigorous plant will shield and protect more delicate plants nearby.

Repelling Pests - Companion planting can be a good and effective organic pest management system. Plants that repel unwanted pests, or which lure pests away can protect more vulnerable plants.

Attracting Pollinators - Planting in close to others which produce a surplus of nectar and pollen can increase the population of beneficial insects in their vicinity, which will benefit other plants nearby.

Mutual Plant Health Benefits - Growing plants next to good bedfellow companions can improve the overall health of both plants.

Soil Structure Benefits - One plant’s root system can easily provide soil structure benefits for adjoining plants. For example, plants with long taproots like carrots and parsnips will break open the soil and draw on nutrients deep within the soil. This can benefit paired plants that have shallow root systems.

Row Cropping - Planting alternate rows of crops of various species can provide benefits for various plant pairs.

Water retention - Closely planting ground cover plants can reduce evaporation from the soil, benefiting taller plants companions.

Some other Benefits of Companion Planting include:

Nasturtiums have a unique scent that repels many insect pests

Alyssum attracts bees and other beneficial insects such as hover flies and lady beetles that control aphids

Basil has a strong scent that repels many insect pests.

Borage is a companion plant for tomatoes, squash and strawberries. Deters many pests.

Calendula flowers releases a sticky substance on their stems that attract and trap aphids

Caraway helps breakdown heavy soils and improves soil structure.

Catnip repels many insect pests, ants and rodents.

Chamomile attracts beneficial insects and pollinators and deters flies and mosquitoes

Chevril is a companion to radishes and leafy greens.

Chives and Garlic repel aphids

Chives are a good general purpose companion plant for most herbs and vegetables. makes a good garden buddy for rosemary is sage. However, rosemary is a fantastic complement to many vegetables.

Dill improves growth and health of cabbage.But do not plant near carrots.

Elderberry is a general insecticide

Fennel repels ants, flies and fleas.

French Marigold exudes a root secretion that helps to kill nematodes in the soil. It also repels white fly amongst tomatoes.

Garlic helps keep aphids away.

Horseradish is a good companion plant for potatoes.

Hyssop is a companion plant for cabbages and grapes, and also helps keep cabbage moths at bay.

Marigolds (Calendula) are a workhorse companion plant deterring insect pests and keeping the soil free of nematodes.

Mint repels cabbage white moth.

Nasturtium has a unique scent that repels many insect pests

Oregano is a good all-purpose plant for repelling most insect pests.

Parsley pairs well with tomatoes and asparagus.

Peppermint repels white cabbage moths

Petunia repels many insect pests.

Pyrethrum repels many insect pests.

Rosemary and Sage are good universal companion plant for carrots, cabbage, beans and sage. It also repels cabbage moths, bean beetles, and carrot flies.

Sage protects cabbages from cabbage white moth.

Summer Savory pairs well with beans, cabbage and onions. It repels white cabbage moths.

Tansy is another good, versatile companion plant for fruit trees, roses and raspberries. It deters a wide range of insect pests

Tarragon deters insect pests

Thyme deters cabbage worms.

Zinnias attract ladybugs into the garden and repel like cabbage flies.

Good Bedfellow Plants for Vegetables

Plant Good Bedfellow For
Anise coriander
Basil tomato, bell peppers
Bee balm Tomato
Borage squash, tomato, strawberry, bean
Chamomile cabbage, most herbs, cucumber, melon, onion
Chervil radish
Chives grapes, tomato, carrot
Coriander anise
Dandelion many fruit trees
Dead nettle potato
Dill lettuce, onion, cabbage family
Dill, Immature tomato, bell peppers
Garlic beet, cabbage family
Horseradish potato
Hyssop grape, cabbage
Larkspur cabbage family, beans
Lovage beans
Marigold potato, tomato
Mint pea, tomato, cabbage family
Mustards fruit trees, grape, beans
Nasturtium radish, cucumber,
Onion cabbage family, lettuce, strawberry, beet
Oregano pumpkin, squash
Pigweed corn, melon
Rosemary beans
Rue figs
Sage tomato, carrot, strawberry, marjoram, cabbage family
Savories bean, onion
Summer savory melon
Sow thistle melon,cataloupe
Tansy most berries, blackberry, raspberry, strawberry
Tarragon most vegetables
Thyme potato, strawberry, eggplant, tomato
Yarrow Most herbs

Bad Bedfellows for Vegetables

Plant Bad Bedfellow For


Beets climbing bean
Cabbage strawberry
Chives peas, beans
Chrysanthemum lettuce
Coriander fennel
Dill tomato, carrot
Fennel bell pepper, beans
Garlic peas, beans
Hyssop radish
Kohlrabi tomato
Larkspur beet
Mustard turnip
Onion peas, beans, sage
Pole bean beets
Potato turnip, pumpkin, squash
Rue basil, cabbage, sage
Sage onion
Shallot bean
Tansy collard
Tomato kohlrabi

Companion Plants that Repel Insect Pests

Pest Repellent Plant as Companions
Ant mint, tansy
Aphid spearmint, peppermint, nasturtium, mustard, marigold, garlic, fennel, eucalyptus, coriander, clover, chives, including catnip and Most aromatic herbs
Asparagus beetle tansy, tomato, basil, calendula, nasturtium, parsley,
Cabbage butterfly tansy
Cabbage looper thyme, spearmint, sage, rosemary, peppermint, pennyroyal, onion, nasturtium, hyssop, garlic, dill and catnip
Cabbage maggot garlic, sage, tansy, thyme, marigold, radish
Carrot fly tansy, sage, rosemary, onion, nasturtium, lettuce, leek and basil
Codling moth garlic
Colorado potato beetle catnip, nasturtium, onion, coriander, marigold, tansy
Corn earworm cosmos, thyme, geranium, marigold
Cucumber beetle tansy, rue, radish, nasturtium, marigold, corn and catnip
Cutworm tansy, spiny amaranth
Flea beetle tansy, spearmint, rue, peppermint, nasturtium, marigold and catnip
Flies tansy, basil
Imported Cabbageworm borage, thyme, tansy, sage, pennyroyal, onion, nasturtium, peppermint, geranium, garlic and dill
Japanese beetle geranium, tansy, marigold, nasturtium, garlic, chives and catnip
Leafhopper geranium, petunia
Mexican bean beetle garlic, rosemary, marigold, nasturtium, savories
Mosquito basil
Nematodes calendula, French marigold
Peach borer garlic
Pests in general oregano
Slug and snail rosemary, fennel, garlic
Spider mite coriander, dill
Squash bug tansy, spearmint, radish, petunia, peppermint, nasturtium, marigold and catnip
Squash vine borer radish
Tomato Hornworm dill, basil, borage, calendula, thyme
Whitefly nasturtium, peppermint, thyme, basil