Following is a list of proven plant companions and enemies, that is, plants that prosper in the company of other plant species and plants to actually hinder growth.
Plant Likes Dislikes Amaranth Potatoes, onions, corn ----- (keep thinned) Anise Coriander ----- Asparagus Parsley, tomatoes Mint Basil Tomatoes Rue Beans (all) Carrots, cauliflower, onions, garlic cukes, cabbage, potatoes shallots, chives celery, strawberries gladiolus Broad Beans Corn (likes particularly) kohlrabi Pole Beans radishes sunflowers, beets (like particularly) Bee Balm tomatoes field mustard Borage strawberries ----- Nasturtiums around fruit trees ----- Broccoli & Cabbage Dill, celery, camomile, tomatoes, pole sage, potatoes, beets, beans strawberries onions, peppermint, rosemary Carrots Onions, radishes, lettuce, Dill tomatoes, peas, chives Cauliflower Celery tomatoes, dill, strawberries Celeriac & Celery Leeks, tomatoes, corn Bush beans Collard Greens Tomatoes ----- Coriander Anise Fennel Corn Morning Glory, potatoes, ----- beans, cukes, pumpkin, squash, melons, sunflowers Cukes Morning Glory, potatoes, potatoes & beans, cukes, pumpkin, aromatic herbs squash, melons, sunflowers Dill Cabbage Carrots Eggplant Green Beans ----- Fennel ----- most plants Flax Carrots & potatoes ----- Kohlrabi Onions, beets, cukes strawberries tomatoes, pole beans Lettuce Onions, strawberries, ----- carrots, cukes radish Lily of the Valley ----- Narcissus Pumpkin Corn potatoes Radish Beets, spinach, carrots, Hyssop parsnips, cukes, squash melons Rhubarb Columbines, roses, ----- wallflowers, garlic, onions Sage Cabbage family, carrots cukes rosemary Spinach strawberries ----- Sunflowers cukes potatoes, pole beans
Two-Level Planting Companions
Vegetables which occupy different soil strata often make good companions. Among these are asparagus with parsley and tomatoes, beets with kohlrabi, beets with onion, leek with vine plants, garlic with tomatoes, carrots with peas and strawberries with bush beans.
Many combinations like this are possible, enabling the gardener with little space to virtually double the yield of her/his garden, and at the same time improve the health and flavour of the vegetables planted together.
Do not plant together plants that are competing for the same space and light, such as sunflowers and pole beans, or plants whose root excretions react unfavourably on each other, such as carrots and dill.