Companion Planting Guide

Companion planting is a method of arranging your plantings according to which types of plants are potentially beneficial to one another. Companion planting may reduce competition for water and nutrients, decrease pest and disease problems, and possibly increase vegetable production.

Almost any article on companion planting references the Native American “Three Sister Planting”. This age old grouping involves growing corn, beans and squash – often pumpkin - in the same area. As the corn stalks grow, beans naturally find support by climbing up the stalk. Beans, as all legumes, fix nitrogen in the soil, which supports the large nutritional needs of corn. Squash grows rapidly and the large squash leaves shade out weeds and serve as natural weed block. Good plant companions work in support of each other.

Many long time gardeners swear that growing certain plants together improves flavor as well. While science hasn’t found support for some of the benefits of companion planting, there is support for the above information. Garden wisdom and experience supports these traditional beneficial plant companions.

Here are combinations found to be beneficial over time from Todd Weinmann of North Dakota State University Agriculture Extension:

ASPARAGUS - Companions: Basil, parsley, tomato. Ally: Pot marigold deters beetles.

BEANS - Companions: Beet (to bush beans only), cabbage family, carrot, celery, chard, corn, cucumber, eggplant, pea, potatoes, radish, strawberry. Enemies: Garlic, onion and shallot stunt the growth of beans. Allies: Marigold deters Mexican bean beetles. Nasturtium and rosemary deter bean beetles. Summer savory deters bean beetles, improves growth and flavor.

BEETS - Companions: Bush beans, cabbage family, lettuce, onion. Ally: Garlic improves growth and flavor. Enemies: Pole beans and beets stunt each other's growth.

CABBAGE FAMILY (Broccoli, Brussels sprouts, cabbage, cauliflower, Chinese cabbage, kale and kohlrabi) - Companions: Beet, celery, chard, cucumber, lettuce, onion, potato, spinach. Allies: Chamomile and garlic improve growth and flavor.

Catnip, hyssop, rosemary and sage deter cabbage moth. Dill improves growth and health. Mint deters cabbage moth and ants, improves health and flavor. Nasturtium deters bugs, beetles, aphids. Southernwood deters cabbage moth, improves growth and flavor. Tansy deters cabbageworm and cutworm. Thyme deters cabbageworm.

Enemies: Kohlrabi and tomato stunt each other's growth.

CARROTS - Companions: Bean, lettuce, onion, pea, pepper, radish, tomato. Allies: Chives improve growth and flavor. Rosemary and sage deter carrot fly. Enemy: Dill retards growth.

CELERY - Companions: Bean, cabbage family and tomato. Allies: Chives and garlic deter aphids. Nasturtium deters bugs and aphids.

CHARD - Companions: Bean, cabbage family and onion

CORN - Companions: Bean, cucumber, melon, parsley, pea, potato, pumpkin, squash. Enemies: Tomatoes and corn are attacked by the same worm. Allies: Odorless marigold and white geranium deter Japanese beetles. Pigweed raises nutrients from the subsoil to where the corn can reach them.

CUCUMBER -Companions: Bean, cabbage family, corn, pea, radish, tomato Enemy: Sage is generally injurious to cucumber. Allies: Marigold deters beetles.

Nasturtium deters aphids, beetles and bugs, improves growth and flavor.

Oregano deters pests in general. Tansy deters ants, beetles, bugs, flying insects.

EGGPLANT -Companions: Bean, pepper. Allies: Marigold deters nematodes.

LETTUCE -Companions: Beet, cabbage family, carrot, onion, radish, strawberry. Allies: Chives and garlic deter aphids.

MELONS -Companions: Corn, pumpkin, radish, squash. Allies: Marigold deters beetles. Nasturtium deters bugs and beetles. Oregano provides general pest protection

ONlONS - Companions: Beet, cabbage family, carrot, chard, lettuce, pepper, strawberry, tomato. Enemies: Onions stunt bean, pea. Allies: Chamomile and summer savory improve growth and flavor. Pigweed raises nutrients from subsoil and makes them available to the onions. Sow thistle improves growth and health.

PARSLEY - Companions: Asparagus, corn, tomato

PEAS -Companions: Bean, carrot, corn, cucumber, radish, turnip. Allies: Chives deter aphids. Mint improves health and flavor. Enemies: Garlic and onion stunt the growth of peas.

PEPPERS -Companions: Carrot, eggplant, onion and tomato

POTATOES - Companions: Beans, cabbage family, corn, eggplant, pea. Enemies: Tomatoes and potatoes are attacked by the same blight. Allies: Horseradish, planted at the corners of the potato patch, provides general protection. Marigold deters beetles.

PUMPKINS - Companions: Corn, melon, squash. Allies: Marigold deters beetles. Nasturtium deters bugs, beetles. Oregano provides general pest protection.

RADISHES -Companions: Bean, carrot, cucumber, lettuce, melon, pea. Allies: Chervil and nasturtium improve growth and flavor. Enemy: Hyssop

SPINACH -Companions: Cabbage family, strawberry

SQUASH- Companions: Corn, melon, pumpkin. Allies: Borage deters worms, improves growth and flavor. Marigold deters beetles. Nasturtium deters squash bugs and beetles. Oregano provides general pest protection.

STRAWBERRY- Companions: Bean, lettuce, onion, spinach, thyme. Enemy: Cabbage. Allies: Borage strengthens resistance to insects and disease. Thyme, as a border, deters worms.

TOMATOES - Companions: Asparagus, carrot, celery, cucumber, onion, parsley, pepper. Enemies: Corn and tomato are attacked by the same worm. Mature dill retards tomato growth. Kohlrabi stunts tomato growth. Potatoes and tomatoes are attacked by the same blight. Allies: Basil repels flies and mosquitoes, improves growth and flavor. Bee balm, chives and mint improve health and flavor.

Borage deters tomato worm, improves growth and flavor. Dill, until mature, improves growth and health. Once mature, it stunts tomato growth. Marigold deters nematodes. Pot marigold deters tomato worm and general garden pests,

TURNIPS - Companion: Pea