Companion Planting Guide: What Grows Well Together
Companion planting means placing crops next to partners that help them and away from ones that hinder them. Good neighbours can repel pests, enrich the soil, offer shade or support, and use space more efficiently; poor ones compete for light and nutrients or share diseases. The pairings below are drawn from aimanac's crop database to help you plan a healthier, higher-yielding vegetable garden.
What is companion planting
Companion planting is choosing which vegetables share a bed based on how they affect one another. Some plants deter their neighbours' pests, some fix nitrogen that feeds hungry crops, and some simply stay out of each other's way by rooting at different depths.
It is not magic, and effects vary with soil and climate, but a few reliable pairings and a handful of combinations to avoid can noticeably cut pest pressure and competition. Use it as a planning guide, not a strict rule.
Good companions
These well-known combinations tend to help each other through pest control, nitrogen fixing, or efficient use of space.
| Crop | Grows well with | Why |
|---|---|---|
| Tomato | Basil, onion, garlic, chives | Repel pests and mask tomato scent |
| Basil | Tomato, peppers | Deters pests, may aid growth |
| Carrot | Onion, leek, chives | Alliums repel carrot fly |
| Carrot | Radish, lettuce | Radish loosens soil; roots don't clash |
| Onion | Cabbage, kale, beetroot | Deters aphids and cabbage pests |
| Bush bean | Cucumber, potato, zucchini | Beans fix soil nitrogen |
| Pea | Carrot, cucumber, spinach | Peas fix nitrogen for neighbours |
| Sweet corn | Beans, squash | Three Sisters: support and nitrogen |
| Cabbage | Dill, celery, onion | Dill draws pest-eating insects |
| Broccoli | Dill, celery | Attracts beneficial predatory insects |
| Cucumber | Radish, beans, peas | Radish deters cucumber beetles |
| Lettuce | Radish, onion, carrot | Neighbours deter pests, share space |
| Tomato | Asparagus | Tomato repels asparagus beetle |
| Strawberry | Garlic, lettuce | Garlic deters disease and pests |
| Kale | Onion, beetroot | Onion lowers pest pressure |
| Beetroot | Onion, kohlrabi | Compatible roots; onion deters pests |
| Brussels sprouts | Onion, dill | Deter cabbage moths and aphids |
| Sweet pepper | Basil, onion | Basil masks scent; onion repels pests |
| Eggplant | Beans, thyme | Beans feed soil; thyme deters pests |
| Potato | Bush bean, horseradish | Beans feed soil; horseradish repels pests |
| Carrot | Leek | Leek deters carrot fly |
| Cauliflower | Celery, dill | Draw predators, ease pest pressure |
| Spinach | Peas, strawberry | Peas fix nitrogen; light ground cover |
| Pole bean | Lettuce, spinach | Trellis shade extends cool-season greens |
Keep apart
These combinations tend to compete, interfere chemically, or share pests and diseases, so give them separate beds.
| Crop | Avoid near | Why |
|---|---|---|
| Fennel | Almost all vegetables | Allelopathic; stunts most neighbours |
| Tomato | Potato | Both nightshades; shared blight risk |
| Tomato | Cabbage, broccoli, cauliflower | Compete and interfere for nutrients |
| Tomato | Sweet corn | Compete for nutrients and light |
| Potato | Squash, cucumber | Heavy feeders compete for nutrients |
| Potato | Melon, watermelon | Compete strongly underground |
| Potato | Spinach | Potatoes crowd spinach roots |
| Cabbage | Strawberry | Strawberries compete strongly |
| Kale | Strawberry | Brassica compounds inhibit strawberry |
| Onion | Asparagus, parsnip | Onions compete with these crops |
| Beans | Peppers | Slight competition lowers pepper yield |
| Beans | Horseradish | Root exudates inhibit bean roots |
| Cucumber | Sage | Sage inhibits cucumber growth |
| Parsley | Lettuce | Parsley competes for nutrients |
| Celery | Sweet corn | Corn outcompetes celery |
Putting it to work in a raised bed
Start with the crop that anchors each bed, surround it with two or three good companions, and move its listed antagonists to another bed. In a raised bed, tuck shallow-rooted lettuce or radish between deeper carrots or beside tomatoes, and let beans or peas share space with the heavy feeders they enrich.
Keep fennel in a pot or a bed of its own, as it discourages almost everything. Rotate nightshades and brassicas each year to limit disease, and remember these pairings are guidelines: your soil, climate and layout have the final say.