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/HyssopRadish
AsparagusFennel, Garlic, Onions, Potatoes
Beetroot/BeetsBeans
Brassica (cabbage, kale, broccoli, etc)Strawberries, Lettuce, Corn, Dill, Eggplant/Aubergine, Peppers, Radishes, Rue, Tomatoes
CarrotsParsley, Celery, Dill
CeleryCorn
ChrysanthemumLettuce
Coriander/CilantroFennel
CornBrassicas, Celery, Eggplant/Aubergine, Fennel, Tomatoes
CucumberBasil, Rosemary, Sage, Fennel, Brassicas, Potatoes
DillCarrots, Tomatoes, Onions, Lettuce, Brassicas
FennelAsparagus, Beans, Cilantro/Corriander, Cucumber, Peppers
GarlicAsparagus, Beans, Peas, Sage
KohlrabiTomatoes, Peppers, Beans
LarkspurBeetroot/Beets
Onions, Shallots, Garlic, Chives, LeeksAsparagus, Beans, Dill, Peas, Sage
ParsnipsCarrots
Peas, Beans and other legumesChives, Garlic, Onions, Potatoes, Pumpkin and Winter Squash
PeppersCabbage, Broccoli, Cauliflower, Fennel, Kohlrabi
PotatoesAsparagus, Cucumbers, Peas, Radishes, Pumpkin and Winter Squash, Tomatoes, Spinach, Sunflower, Turnip
RadishBroccoli, Cauliflower, Cabbage, Hyssop, Potatoes, Turnip
RueBasil, Cabbage, Sage
SunflowerMost plants
TansyBrassicas
TomatoesBrassicas, Corn, Dill, Fennel, Potatoes
TurnipPotatoes, Radish
Black Walnut treeMost plants, especially azaleas, birch and pine trees, tomatoes, peppers, eggplants, potatoes
Winter squash/PumpkinCorn, Peas, Radishes, Potatoes
Plants that do not grow well together