Planting in groups, in a polyculture or in a mixed bed has so many advantages, from disguising the individual plants from potential pests to providing support on a microbial level and through to just looking good together! But there are some plants that don’t work so well as companions.
- Some because they are heavy feeders of the same nutrients and therefore, would compete for the available nutrients.
- Others contain or give off substances that can actively inhibit the growth of plants around them (Allelopathy).
- While another selection may suffer from the same pests and diseases and so planting them together may increase their susceptibility.
Don’t be afraid to try companion planting or growing in mixed groupings. Much of the joy of gardening is in the experimenting and learning from the results in your own garden or growing space.
I often ignore ‘the rules’ and group plants together because I like the aesthetics of them in a group and am not so concerned about the volume or size of harvest. However, where space is of a premium, it may be worth taking the suggestions below into consideration more to give you the best harvest from your growing space.
The chart below gives some useful suggestions of plants that generally do not grow so well together, but again, you may want to experiment for yourself and discover what works best in your garden.
Agastache/Hyssop | Radish |
Asparagus | Fennel, Garlic, Onions, Potatoes |
Beetroot/Beets | Beans |
Brassica (cabbage, kale, broccoli, etc) | Strawberries, Lettuce, Corn, Dill, Eggplant/Aubergine, Peppers, Radishes, Rue, Tomatoes |
Carrots | Parsley, Celery, Dill |
Celery | Corn |
Chrysanthemum | Lettuce |
Coriander/Cilantro | Fennel |
Corn | Brassicas, Celery, Eggplant/Aubergine, Fennel, Tomatoes |
Cucumber | Basil, Rosemary, Sage, Fennel, Brassicas, Potatoes |
Dill | Carrots, Tomatoes, Onions, Lettuce, Brassicas |
Fennel | Asparagus, Beans, Cilantro/Corriander, Cucumber, Peppers |
Garlic | Asparagus, Beans, Peas, Sage |
Kohlrabi | Tomatoes, Peppers, Beans |
Larkspur | Beetroot/Beets |
Onions, Shallots, Garlic, Chives, Leeks | Asparagus, Beans, Dill, Peas, Sage |
Parsnips | Carrots |
Peas, Beans and other legumes | Chives, Garlic, Onions, Potatoes, Pumpkin and Winter Squash |
Peppers | Cabbage, Broccoli, Cauliflower, Fennel, Kohlrabi |
Potatoes | Asparagus, Cucumbers, Peas, Radishes, Pumpkin and Winter Squash, Tomatoes, Spinach, Sunflower, Turnip |
Radish | Broccoli, Cauliflower, Cabbage, Hyssop, Potatoes, Turnip |
Rue | Basil, Cabbage, Sage |
Sunflower | Most plants |
Tansy | Brassicas |
Tomatoes | Brassicas, Corn, Dill, Fennel, Potatoes |
Turnip | Potatoes, Radish |
Black Walnut tree | Most plants, especially azaleas, birch and pine trees, tomatoes, peppers, eggplants, potatoes |
Winter squash/Pumpkin | Corn, Peas, Radishes, Potatoes |