There are plants that grow well together and plants that are problematic if planted next to each other. This is the principle of companion planting. Sustainable garden practices or permaculture promote polyculture, mixing species, rather than monoculture, planting only one specie. For best results, you should do crop rotation, have good soil and correct spacing between plants.
Native Americans have been practicing companion planting for many years. They grow the “Three Sisters” together, which are corn, beans and squash. Beans use corn stalks for support, while stabilizing corn and providing nitrogen to the soil. Squash prevents moisture evaporation and weeds since they are a sprawling crop that gives shade.
What are the Benefits of Companion Planting?
Some plants attract beneficial insects so other plants can grow or they can also be a repellent for pests that can be harmful. Animals dislike smells of certain plants. For example, raccoons cannot tolerate the smell of cucumbers. Rabbits will leave alone your lettuce or cabbage if you plant onions between them.
Taller plants can also provide shade for smaller plants that may require it, such as lettuce that does not tolerate heat. Vines can cover the ground, while stalks grow upright, thus allowing two plants to grow in the same space.
When choosing species to plant next to each other, it is important to consider their nutrient requirements. The idea is to plant varieties that need different kinds of nutrients, so that the other plant can thrive. When one plant absorbs certain substances, it can change the biochemistry of the soil in favor of surrounding plants. Without companion planting you would probably have a monoculture and that depletes the soil from nutrients, forcing you to buy chemical fertilizers.
Plant heavy feeders, such as tomatoes and cabbages, then legumes to help the soil recover. Light feeders (root vegetables, bulbs, herbs and protective flowers) can be adding before the start of the following season. Do not plant together crops that are susceptible to the same diseases or pests.
There are many benefits of planting plants together. Crops like beans, legumes and peas create nitrogen in the soil. Companion planting done with plants that have long taproots help bring nutrients up for shallow rooted plants. Sprawling crops help minimize space for weeds, allowing better growth of upright plants.
Companion planting should take into consideration how much space apart is required by each plant. You can do an average between the requirements of both. Make sure shorter herbs or vegetables are not completely shaded out. Also, plant taking into consideration the water needs of the companions.
Companion planting with Flowers and Herbs
Flowers are great for companion planting, since they attract beneficial insects when flowering. Nasturtium, for example, lures garden pests, aphids, and squash bugs away from plants. If you plant them next to fava beans, black flies will eat the flowers instead. Or plant brassica next to crops like cabbage to save the crop from cabbage worms and caterpillars.
Zinnias are great for vegetable companion planting as they attract ladybugs. Sweet alyssum, calendula and cosmos attracts hoverflies which devour aphids. Dill attracts ladybugs which eat spider mites and aphids. Those that have mice problems can plant catnip. Make sure to include flowers and herbs in your companion planting list.
Chamomile attracts parasitic wasps which feed many harmful pests. Herbs such as basil, borage, chives, cilantro, oregano, mint, lavender, rosemary, sage and thyme are great at taking care of pests in your garden, as well as attracting beneficial insects.
For this companion planting guide we are going to include eight plant families. Make sure you never plant the allium family with legumes, because plants in the first group produces a substance that gets on the soil killing the beneficial bacteria needed by bean roots, preventing them from fixating nitrogen in the soil and growing.
- Nightshades: eggplants, potatoes, tomatoes and peppers. Plants in this family should not be planted near each other as they can all suffer from blight.
- Broccoli: bok choy, brussel sprouts, broccoli, cabbages, collards, kale, horseradish, radish, mustard, turnips, and watercress.
- Carrots: anise, carrots, celery, chervil, caraway, cilantro, cumin, dill, fennel, parsnips and parsley. Prefers direct seeding and has a long growing season.
- Allium: asparagus, chives, garlic, onions, leeks, shallots and scallions.
- Mint: basil, catnip, hyssop, lavender, marjoram, lemon balm, white horehound, oregano, rosemary, savory, sage and thyme.
- Legume: beans, snap peas, lentils and fava beans. They increase nitrogen in the soil and most need trellises.
- Squash: pumpkin, cucumbers, melons, gourds and squash. This family prefers full sun, consistent watering and warm temperatures. Can be grown on trellises or on the ground.
- Beetroot: beets, quinoa, swiss chard, spinach and lamb’s quarter. Bolts in hot weather, prefers spring climate.
Companion Planting Chart
|Plant||Good Companion||Bad Companion||Observations|
|Asparagus||Asters, Basil, Carrots, Cilantro, Calendula, Dill, Marigolds, Nasturtiums, Oregano, Parsley, Peppers, Petunias, Sage, Thyme, Tomatoes||Onion, Garlic, Potatoes||Calendula, tomatoes, and petunias are thought to deter asparagus beetles.|
|Beans||Beets, Broccoli, Carrots, Chard, Cabbage, Cauliflower, Corn, Cucumber, Eggplant, Marigolds, Peas, Radishes||Beets, Members of the Allium Family such as Chives, Leeks, Garlic and Peppers||Fixes nitrogen deficiency in soil. Nasturtiums and Rosemary deter bean beetles|
|Basil||Asparagus, Anise, Beans, Beets, Bell Peppers, Cabbage, Chamomile, Chili Peppers, Eggplant, Lettuce, Marigolds, Oregano, Potatoes, Peppers, Purslane, Tomatoes||Sage, Rue||Repels flies, mosquitoes, thrips. Improves vigor & flavor in tomatoes, peppers, and lettuce. Companion planting with chamomile and anise help increase the flavor of basil. Purslane is used to shade the soil around basil plants, helping them to remain fresh in hot weather.|
|Beets||Broccoli, Brussels Sprouts, Bush Beans, Cabbage, Cauliflower, Chard, Corn, Garlic, Leeks, Lettuce, Mint, Sage, Kohlrabi, Onions||Charlock, Field Mustard, Pole Beans||Pole beans compete with beets for growth. Beets grow especially well with kohlrabi. They become more flavorful when grown near garlic. Composted beet leaves increase magnesium in the soil, thus aiding photosynthesis.|
|Broccoli||Basil, Beets, Bush Beans, Carrots, Celery, Chamomile, Cucumber, Dill, Garlic, Hyssop, Lettuce, Marigolds, Mint, Nasturtiums, Onions, Radishes, Rosemary, Sage, Spinach, Swiss Chard, Thyme||Oregano, Strawberries, Tomatoes, Asparagus, Cantaloupe, Climbing Beans, Mustard, Peppers, Pumpkins, Sweet Corn, Watermelon||Rosemary can repel cabbage fly, which is bad for broccoli.|
|Cabbage||Garlic, Nasturtium, Sage, Beets, Potatoes, Chamomile, Celery, Chard, Lettuce, Spinach, Onions||Pole Beans, Strawberries, Tomatoes, Eggplant, Kohlrabi||Hyssop, mint, and sage can repel cabbage moths and stop cabbage worms. Nasturtiums deters pests such as beetles and aphids, while garlic repels insects.|
|Carrots||Beans, Cabbage, Chives, Early potatoes, Leeks, Lettuce, Onions, Peas, Peppers, Tomatoes, Radishes, Rosemary, Sage||Dill, Parsnip, Parsley||Chives improve flavor and growth of carrots, as well as deter mites, flies and aphids. Companion planting with rosemary, sage and leeks can repel carrot fly. Members of the parsley family should not be near carrots since they can cross pollinate and also can reduce yields.|
|Corn||Beans, Cucumber, Dill, Marigolds, Marjoram, Melons, Peas, Pumpkin, Potato, Squash, Sunflowers, Zucchini Beans (pole)||Tomatoes||Beans (pole beans help provide structural support) and peas help fix nitrogen levels. Sunflowers are also a good structure for corn and can be a windbreaker. Dill protects against aphids and mites, while marigolds prevent nematodes in the soil. Tomato hornworms and corn earworms like both plants.|
|Cucumber||Beans, Borage, Celery, Dill, Lettuce, Nasturtiums, Oregano, Pea, Radish, Sunflowers, Tansy||Cauliflower, Melons, Potatoes, Basil||Dill protects cucumbers against mites and aphids, while oregano prevents pests in general. Nasturtium deters aphids, beetles and bugs, at the same time improving growth and flavor like borage. Tansy stops flying insects, bugs, beetles, and ants. Sunflowers are good trellis and shelter for cucumbers.|
|Lettuce||Basil, Beets, Cabbage, Carrots, Chives, Onions, Radish, Scallions, Spinach, Strawberries||Beans, Cole crops, Parsley||Basil improves the flavor and growth of lettuce. Radish traps flea beetles, while companion planting with garlic, onion and chives deter pests and aphids by masking the scent of lettuce.|
|Onions||Broccoli, Beets, Chamomile, Cabbage, Carrots, Chard, Lettuce, Peppers, Strawberry, Summer Savory, Tomatoes||Beans, Peas||Chamomile and summer savory can improves growth and flavor. Onions naturally protect against borers, mites, slugs, and cutworms, as well as maggots of all types.|
|Peas||Alyssum, Beans, Carrot, Chives, Corn, Cucumber, Mint, Radish, Turnip||Onion, Garlic, Potatoes||Alyssum brings beneficial insects that are pollinators and green lacewings that eat aphids. Chives also prevent aphids. Mint improves flavor and health. Do not plant onion and garlic near peas, as they will stunt the growth.|
|Peppers||Basil, Carrots, Marjoram, Onions, Oregano, Parsley, Tomatoes||Fennel, Beans||Basil, oregano, and marjoram have a protective, insecticidal quality.|
|Potatoes||Basil, Beans, Brassicas, Calendula, Catmint, Celery, Cilanto, Garlic, Horseradish, Eggplant, Lettuce, Marigolds, Onions, Peas, Radishes, Spinach, Squash, Tansy||Asparagus, Broccoli, Brussels Sprouts, Cabbage, Cauliflower, Carrots, Corn, Cucumbers, EggplaKohlrabi, Melons, Peppers, Pumpkin, Raspberries, Sunflowers, Strawberries, Tomatoes||Companion planting with beans can make potato tubers bigger. Calendula, catmint (can bring cats to the garden so plant in pots on the edge of the plot), tansy and horseradish ward off Colorado potato beetles. Cilantro can protect also protect against spider mites and aphids. Corn is a have feeder so it should not be planted together, otherwise you will get small potatoes. Cucumbers, tomatoes, and raspberries can attract harmful pests to potatoes.|
|Pumpkin and Squash||Beans, Borage, Calendula, Corn, Marigolds, Nasturtiums, Oregano, Squash||Potatoes||Borage attracts pollinators and improves flavor and growth. Oregano provides general protection from pests, while nasturiums protect against pumpkin and squash beetles and calendula deters beetles and root nematodes. Do not grow pumpkin with other winter squash, since they have the same growing requirements.|
|Radish||Peas Beets, Carrots, Peas, Spinach, Beans Beets, Cabbage, Carrots, Chervil, Chives, Cucumbers, Kale, Lettuce, Nasturtium, Spinach, Squash||Cabbage, Cauliflower, Brussel Sprouts, Hyssops||Lettuce helps tenderize summer radish, while nasturtium and chervil improves flavor and growth. Kale grows is good for companion planting with radish as it deters flea beetle, since it is a trap crop.|
|Spinach||Beans, Brassicas, Cilantro, Eggplants, Leeks, Lettuce, Peas, Radish, Strawberries||Parsnips, Potatoes||Spinach and strawberries grow great together. Beans and peas provide shade. Cilantro repels insects.|
|Strawberries||Beans, Borage, Caraway, Chives, Garlic, Lettuce, Onions, Peas, Sage, Squash, Spinach, Thyme||Brassicas, Cabbage Family, Eggplants, Fennel, Kohlrabi, Peppers, Potatoes, Tomatoes||Really benefits from companion planting.|
|Tomatoes||Asparagus, Basil, Beans, Borage, Calendula, Carrots, Celery, Chives, Cucumbers, Garlic, Lettuce, Marigolds, Mint, Nasturtium, Onion, Parsley, Peppers, Bee Balm||Brassicas, Corn, Dill, Fennel, Kohlrabi, Potatoes||Chives improve flavor and health. Calendula deters pests in general, parsley draws insects away and asparagus repels nematodes. Basil as companion planting repels aphids, spider mites, mosquitos and white flies, while at the same time attracts bees (improving pollination) and increasing the health and flavor of tomatoes. Corn attracts bad pests, potatoes spread blight and kohlrabi stunts growth.|
|Zucchini||Beans, Corn, Dill, Garlic, Marigolds, Nasturtiums, Oregano, Peas, Radishes, Spinach, Zinnia||Potatoes, Pumpkin||Plant oregano and zinnias to attract pollinators. Companion planting with nasturtium protects zucchini against aphids, and whiteflies.|