Which vegetables grow well together? We check the charts against the evidence.

Companion plants for the crops people ask about most

Each page lists good and bad neighbours, what trials found and what the charts say.

• Tomato21 good neighbours21 pairs tested
• Pepper14 good neighbours22 pairs tested
• Cucumber13 good neighbours10 pairs tested
• Potato5 good neighbours8 pairs tested
• Onion11 good neighbours12 pairs tested
• Squash & pumpkin7 good neighbours5 pairs tested
• Basil10 good neighbours9 pairs tested
• Eggplant11 good neighbours8 pairs tested
• Broccoli10 good neighbours9 pairs tested
• Carrot12 good neighbours9 pairs tested
• Dill10 good neighbours6 pairs tested
• Lettuce18 good neighbours18 pairs tested

All 44 plants

Popular questions

• Can you plant beans and peas together? Yes, with care.
• Can you plant tomatoes and peppers together? It depends.
• Can you plant tomatoes and cucumbers together? Yes.
• Can you plant basil and tomatoes together? Yes.
• Can you plant garlic and onions together? Yes, with care.
• Can you plant watermelon and melons together? Yes, with care.
• Can you plant onions and tomatoes together? Yes.
• Can you plant rosemary and basil together? Yes, with care.

All 260 pairs we can answer

Myths the evidence does not back

Pairs where the charts and the tests we found point in different directions.

• Onions and beansGarden charts say to keep beans away from onions, but the tests we found say otherwise.
• Beets and tomatoesGarden charts say to keep tomatoes away from beets, but the tests we found say otherwise.
• Cabbage and lettuceGarden charts say to keep lettuce away from cabbage, but the tests we found don't back that up.
• Dill and fennelGarden charts say that dill and fennel help each other, but the tests we found say otherwise.
• Fennel and tomatoesGarden charts say to keep tomatoes away from fennel, but the tests we found say otherwise.
• Tomatoes and potatoesGarden charts say to keep potatoes away from tomatoes, but the tests we found say otherwise.

How we check a pair

Four kinds of evidence, kept apart so you can see which one an answer rests on.

• Garden charts

  981 tips from Wikipedia's list of companion plants. 485 of them cite no source at all, and we label them as tradition only.

• Research papers

  319 findings from 212 papers found in Europe PMC. A model sorted each paper by what it found; no person has reviewed them yet, so every finding links to the paper.

• Yield trials

  155 results from 95 field experiments that grew two crops together and measured the harvest against growing them apart.

• Plant families

  Crops from the same botanical family share many pests and diseases, so we flag close relatives as a caution, not a verdict.