[simonj]

This list summarises some commonly held beliefs about the uses of companion plants and compliamentary crops.

More info on organic pest control and containment at my garden blog, link in signature.

Allium--flowering onions, chives, garlic, leek, onion and shallot
Companion to: Roses, carrots, tomato, fruit trees and other vegetables
Repel aphids, weevils, carrot flies, moles, fruit tree borers; controls rust flies; protects tomatoes against red spiders. Protects roses from black spot, mildew and aphids.
BUT is believed to inhibit growth of peas and beans.

Basil
Companion to: Tomato, asparagus
Repels aphids, flies and mites; helps control insect pests such as tomato horn worms, asparagus beetles, and disease.

Beans (Butter, green, snap, string,wax)
Companion to: Beets, carrots,cucumber, corn, aubergine, potato,strawberry
Encourage growth of companion plants. Adds nitrogen to the soil.

Borage
Companion to: Tomato, strawberry, fruit orchards
Repels tomato worms. Adds potassium, calcium and other minerals to soil. Attracts honeybees.

Chamomile
Companion to: Cabbage, onions
Improves growth and flavor--but plant only one plant every 150 feet or so.

Catnip
Companion to: Aubergine. Fresh catnip steeped in water and sprinkled on plants will drive away flea beetles.

Celery
Companion to: Cabbage, leeks, tomato, cauliflower
Improves growth of companion plants. Repels white cabbage butterflies.

Chervil
Companion to: Radish. Improves growth and flavor.

Chive
Companion to: Carrots. Improves growth and flavor.

Coriander
Companion to: Vegetables. Repels aphids. Attracts bees.

Cucumber
Companion to: Sweetcorn, beans, peas, radish, sunflowers
Improves growth. Vines growing with corn help anchor sweetcorn.

Dill
Companion to: Cabbage. Improves growth. Blossoms attract honeybees.

Fennel
Most plants dislike fennel--so plant it away from the vegetable garden.
Its foliage and flowers may attract beneficial insects.

Geranium
Companion to: Cabbage, corn, roses. Repels cabbage worms.

Horseradish
Companion to: Potato. Encourages growth.

Hyssop
Companion to: Cabbage. Improves growth, deters cabbage moth.

Leek
Companion to: Carrots, celery, onions. Improves growth, repels carrot flies.

Marigold
Companion to: Tomato, potato, strawberry, beans, roses
Encourages growth, deters some pests.
Discourages harmful nematodes if they are grown for several seasons in the ground in areas that have nematode infestations.

Mint
Companion to: Tomato, cabbage. Improves flavor and growth

Mustard
Companion to:Cabbage, cauliflower, radish, Brussels sprouts, turnips, collards, kohlrabi
Plant mustard as a trap crop. It attracts numerous insect pests. Remove and destroy it before your main crops can be harmed.

Nasturtiums
Companion to: Cucumber, other vegetables, fruit trees.
Repels aphids,cucumber beetles and white flies.
Acts as trap crop for aphids. Repels borers near fruit trees.

Onion
Companion to: Cabbage, cauliflower, broccoli,beets, tomato, lettuce, strawberry, chamomile, summer savory
Repels aphids, weevils, carrot flies, moles, fruit tree borers; controls rust flies and some nematodes;
Protects tomatoes against red spiders. BUT is believed to inhibit growth of peas and beans.

Oregano
Companion to: Broccoli, brassica's .Repels cabbage butterfly.

Parsley
Companion to: Asparagus tomato, roses.
Deters asparagus beetles.Improves growth. Deters rose beetles.
Nigel from chillington hoes (chillingtonhoes.com) also informed me that parsley is related to carrots and parsnips and will not deter carrot fly and will actually be attacked by them.

Peas
Companion to: Sweetcorn
Adds nitrogen to soil for use by hungry corn plants. Grows well with carrots, turnip, radish, cucumber, beans and potatoes.

Pennyroyal Broccoli,
Companion to: Brussels sprouts, cabbage, other plants. Discourages ants, plant lice, cabbage maggots.

Radish
Companion to: Cucumber. Deters cucumber beetles.
Rosemary

Companion to: Carrots, cabbage, beans Repels carrot flies, bean beetles, cabbage moths.

Sage
Companion to: Carrots, Brassica's. Repels carrot flies, cabbage moths.
Summer savory
Companion to: Green beans. Improves growth, deters bean beetles.

Tansy
Companion to: Cucumber, squash, roses, raspberry, blackberry.
Deters flying insects, striped cucumber beetles, ants, flies, squash.
BUT, attracts cabbage worms.

Thyme
Companion to: Cabbage
Controls flea beetles, cabbage maggots, cabbage worms and white cabbage butterflies.

Wormwood
Companion to: Various plants Deters black flea beetles, cabbage worm butterflies. Highly Poisonous

[michael brenock]

Simonj that is a very comprehensive list and many of them no doubt are true.
michael brenock horticultural advisor (retired)

[Liz D]

This is brilliant- I'm printing this one off for my gardening diary!

Thanks Simonj

[simonj]

Just a correction on the posting.

Nigel from chillington hoes informed me that parsley is actually related to carrots and parsnips and will not deter carrot fly and will be attacked by them.