Companion Planting

Companion planting (allelopathy) is based on the principle that certain plants can attract or repel insects or provide beneficial support to other plants. It can also work the other way around, where one plant can be detrimental to another's growth.

Scientists scoff at gardeners who practice allelopathy and say that we are wasting our time. However, they are quick to mention scientific marvels like the downwind tannin response in Acacia spp when grazed on by herbivores.

Think of it a bit like plant body odour – either it's attractive or it's disgusting… That, in a nutshell, is companion planting. Some plants have a good BO, others have a great BO, and yet others are downright repulsive!

This is not a bad thing, one must just learn to work with nature and use the plants to their best advantage.

Below is a comprehensive list of companion plants. Beneficial companions are listed in green and detrimental are parenthesised in red.

 

Almond:                        garlic, tansy (tomato, potato)
Apple:                            chives, nasturtium, garlic, onion (grasses, potato)
Apricot:                         basil, tansy, garlic (tomato)
Artichoke:                    peas, sunflower, cucumber (potato)
Asparagus:                   parsley, basil, lettuce, tomato (avoid onion)
Basil:                              most vegetables and herbs – especially tomato, asparagus, peppers
Bay Leaf:                       generally beneficial as pest deterrent (not for wet or shady areas)
Beans (Broad):             potato, corn, turnip (onion, garlic, leek, chives, fennel)
Beans (Dwarf/Bush): Swiss chard, beetroot, potato, savory (onion, garlic, leek, chives, fennel)
Beans (Pole/Runner): corn, lettuce, eggplant, cucumber, strawberry, celery, carrot, cauliflower, radish, spinach (onion, garlic, leek, chives, fennel)
Beetroot:                       bush beans, garlic, chives, onion, lettuce, spinach, Swiss chard
Blackberry:                   garlic, rue, tansy (nightshades, fennel)
Blueberry:                     thyme, strawberries (cabbage family)
Borage:                          strawberry, tomato, lettuce
Brinjal/Eggplant:         beans (runner and bush), echinacea, peppers, lettuce (avoid fennel)
Broccoli:                        onion, echinacea, nasturtium, leek, celery, chamomile, sage (rue, tomato, strawberry)
Brussels Sprout:          potato, echinacea, nasturtium, hyssop, sage, thyme (rue, tomato, strawberry)
Cabbage:                        beans, beetroot, celery, echinacea, most herbs, onion, potato, hyssop, sage (rue, tomato, strawberry, grape)
Carrot:                            peas, leek, lettuce, radish, onion, chives, sage
Cauliflower:                  celery, beans, echinacea, cabbage, onion, leek, chamomile (rue, tomato, strawberry)
Celery:                            tomato, cauliflower, cabbage, leek, onion, garlic, beans
Celeriac:                         leek, celery, onion (avoid corn)
Chamomile:                  cabbage, cauliflower, Brussels sprout, broccoli, onion, leek, chives
Chervil:                          dill, coriander, carrot, radish
Chicory:                         carrots, leeks (avoid parsley)
Chilli/Peppers:             cucumber, echinacea, pumpkin, marrow, lovage, bush beans, lettuce (avoid fennel)
Chives:                           parsley, apple, carrot, tomato, potato, eggplant
Comfrey:                       fruit trees, potatoes, tomatoes (none known – use cautiously due to spread)
Coriander:                    dill, chervil, cabbage, carrot, broccoli, Brussels sprout, cauliflower (fennel)
Corn/Mielies:               lettuce, peppers, pumpkin, cucumber, runner beans, peas, melon
Cucumber:                    radish, lettuce, beans, peas, corn, nasturtium (avoid sage)
Dill:                                 cabbage, carrot, brinjal, peppers (avoid fennel)
Echinacea:                    peppers, brinjal, tomato, potato, cabbage, broccoli, Brussels sprout, cauliflower
Endive:                          leek, carrots, beets (avoid parsley)
Fennel:                          generally incompatible with most plants (avoid tomato, beans, coriander, dill, cucumber)
Feverfew:                     cabbage family, tomatoes, fruit trees
Fig:                                 rue, garlic (brassicas)
Garlic:                           apple, peach, nectarine, apricot, almond, tomato, Swiss chard (peas, beans, cabbage, strawberry)
Grapes:                         basil, hyssop, sage, tansy (avoid cabbage family)
Horseradish:               potato, cabbage family, fruit trees (beans)
Hyssop:                         cabbage, broccoli, Brussels sprout, cauliflower
Jerusalem Artichoke: beans, corn (avoid fennel; invasive spread)
Kohlrabi:                       beetroot, Swiss chard, leek, chives, onion (avoid tomato, peppers)
Leek:                              cabbage, celery, onion, celeriac, carrot
Lemon Balm:               fruit trees, tomatoes, squash (avoid near mint)
Lettuce:                         beetroot, strawberry, radish, corn, carrot, cucumber
Lovage:                          most plants, especially peppers and beans
Marigold:                      everything – general pest deterrent
Marrow (All):                parsley, tomato, Swiss chard, spinach, squash, corn, capsicum. See also Zucchini below.
Melon:                            corn, nasturtium
Mint:                               cabbage, tomato (avoid parsley)
Nasturtium:                  apple, cabbage, broccoli, Brussels sprout, cauliflower, kohlrabi, turnip, cucumber, melon, marrow, pumpkin, radish, tomato
Okra:                               basil, lettuce, peppers (avoid fennel)
Onion:                             lettuce, cabbage, carrot, beetroot
Oregano:                        strawberry, peppers, beans, cabbage, broccoli, Brussels sprout, cauliflower, kohlrabi, turnip
Parsley:                          tomato, asparagus, carrot, strawberry, beans (avoid mint)
Parsnip:                          peas, onions, garlic, chives (carrots)
Peach:                             basil, tansy, garlic (avoid tomato)
Peas:                                cucumber, radish, turnip, corn, carrot, beans (avoid onion, garlic, leek, chives)
Peppers/Chilli:              cucumber, echinacea, pumpkin, marrow, lovage, bush beans, lettuce (avoid fennel)
Potato:                            cucumber, sunflower, beans (all), peas, nasturtium, corn (tomato, brinjal, pumpkin)
Pumpkin:                        corn, pole/runner beans, nasturtium (potato, other pumpkins)
Radish:                            peas, lettuce, nasturtium, cucumber
Raspberry:                      garlic, tansy, onion (potatoes, tomatoes)
Rosemary:                      cabbage, carrots, beans (avoid tomato)
Rue:                                  tomato (basil)
Sage:                                carrot, strawberry, grape, cabbage, broccoli, Brussels sprout, cauliflower, kohlrabi, turnip (basil, rue, wormwood)
Savory:                            tomato, beans (all), onion, garlic, leek, chives
Shallot:                           carrot, beetroot, mint
Spinach:                          strawberry, beetroot, most plants
Strawberry:                    borage, lettuce, spinach, Swiss chard, bush beans, onion
Swiss Chard:                  onions, beetroot, cabbage, broccoli, Brussels sprout, cauliflower, kohlrabi, strawberry, turnip
Tansy:                              peach, apricot, almond, nectarine, cabbage, broccoli, Brussels sprout, cauliflower, kohlrabi, turnip
Tarragon:                        generally improves growth of vegetables and herbs
Thyme:                            cabbage, broccoli, Brussels sprout, cauliflower, kohlrabi, turnip
Tomato:                           asparagus, celery, echinacea, parsley, basil, carrot, onion, garlic, chives, leek, nasturtium (rosemary, potato, apricot, peach, almond, dill, fennel)
Turnip:                             peas, broad beans, nasturtium, sage, thyme
Winter Savory:               beans, onion, garlic, tomato
Zucchini:                          nasturtium, corn, beans, marigold (potatoes)