Companion Planting

http://thegardengeeks.net/garden-articles/gardening-how-tos/541-companion-planting-guide

ASPARAGUS

Companions: Basil, parsley, tomato.

Allies: Pot marigold deters beetles.

Enemies:

BEANS

Companions: Beet (to bush beans only), cabbage family, carrot, celery, chard, corn, cucumber, eggplant, pea, potatoes, radish, strawberry.

Allies: Marigold deters Mexican bean beetles. Nasturtium and rosemary deter bean beetles. Summer savory deters bean beetles, improves growth and flavor.

Enemies: Garlic, onion and shallot stunt the growth of beans.

BEETS

Companions: Bush beans, cabbage family, lettuce, onion

Allies:Allies: 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.

Enemies: Dill retards growth.

CELERY

Companions: Bean, cabbage family and tomato

Allies: Chives and garlic deter aphids. Nasturtium deters bugs and aphids.

Enemies: unknown

CHARD

Companions: Bean, cabbage family and onion

Allies: unknown

Enemies: unknown

CORN

Companions: Bean, cucumber, melon, parsley, pea, potato, pumpkin, squash

Allies: Odorless marigold and white geranium deter Japanese beetles. Pigweed raises nutrients from the subsoil to where the corn can reach them.

Enemies: Tomatoes and corn are attacked by the same worm.

CUCUMBER

Companions: Bean, cabbage family, corn, pea, radish, tomato

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.

Enemies: Sage is generally injurious to cucumber.

EGGPLANT

Companions: Bean, pepper

Allies: Marigold deters nematodes. Catnip deters fle beetles

Enemies: unknown

LETTUCE

Companions: Beet, cabbage family, carrot, onion, radish, strawberry

Allies: Chives and garlic deter aphids.

Enemies: unknown

MELONS

Companions: Corn, pumpkin, radish, squash

Allies: Marigold deters beetles. Nasturtium deters bugs and beetles. Oregano provides general pest protection

Enemies: unknown

ONIONS

Companions: Beet, cabbage family, carrot, chard, lettuce, pepper, strawberry, tomato

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.

Enemies: Onions stunt bean, pea.

PARSLEY

Companions: Asparagus, corn, tomato

Allies:

Enemies:

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

Allies:

Enemies:

POTATOES

Companions: Beans, cabbage family, corn, eggplant, pea

Allies:Horseradish, planted at the corners of the potato patch, provides general protection. Marigold deters beetles.

Enemies: Tomatoes and potatoes are attacked by the same blight.

PUMPKINS

Companions: Corn, melon, squash

Allies: Marigold deters beetles. Nasturtium deters bugs, beetles. Oregano provides general pest protection.

Enemies:

RADISHES

Companions: Bean, carrot, cucumber, lettuce, melon, pea

Allies: Chervil and nasturtium improve growth and flavor.

Enemies: Hyssop

SPINACH

Companions: Cabbage family, strawberry

Allies:

Enemies:

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.

Enemies:

STRAWBERRY

Companions: Bean, lettuce, onion, spinach, thyme

Allies: Borage strengthens resistance to insects and disease. Thyme, as a border, deters worms.

Enemies: Cabbage

TOMATOES

Companions: Asparagus, carrot, celery, cucumber, onion, parsley, pepper

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,

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.

TURNIPS

Companion: Pea

Allies:

Enemies: Potato and Pole beans are said to be bad due to root competition