Companion planting has been around since before people wrote gardening books. The Iroquois were interplanting corn, beans, and squash as the Three Sisters when European gardening was still mostly cabbage. And yet most modern gardens ignore i
The science has caught up to what growers already knew: some plants make each other visibly better. Basil planted next to tomatoes really does seem to improve flavor and repel thrips. Onions and carrots really do mask each other’s scent from their respective pests. And some pairings (fennel next to almost anything, walnuts next to nightshades) really do fight.
Which Plants Are Best Friends With Yours?
Free 30-second guide · pick your main crop · get friends + enemies
Why companion planting works
- Pest confusion. Strong-scented plants (herbs, alliums, marigolds) mask the smell of crops that pests hunt by scent. Carrot flies and onion flies both hunt by smel
- Nitrogen fixing. Legumes (beans, peas, clover) pull nitrogen from the air and fix it into the soil. Heavy feeders like corn and cabbage benefit next door, or in a bed that grew legumes last season.
- Physical support. The Three Sisters (corn, pole beans, squash) is a stack: the corn provides a trellis, beans feed the corn, and squash shades the soil to retain moisture.
- Pollinator draw. Borage, calendula, nasturtium, and flowering herbs bring bees to your fruit and vegetable crops. More pollinator visits mean more fruit set.
- Trap cropping. Some plants attract pests preferentially, luring them away from your main crops. Nasturtiums draw squash bugs, radishes lure cucumber beetles.
The Big Ten pairings worth memorizing
- Tomatoes + basil + marigolds. Repels the pests that hit tomatoes hardest.
- Carrots + onions. Mutual pest confusion between the carrot fly and onion fly.
- Corn + pole beans + squash. The Three Sister
- Cucumbers + nasturtiums + radishes. Radishes lure cucumber beetles; nasturtiums confuse them further.
- Strawberries + borage. Pollinator magnet; multiple studies suggest better berry flavor and yield.
- Cabbage + dill + chamomile. Deter cabbage worms without pesticides.
And the pairings to avoid
- Beans and alliums (onions, garlic, chives, leeks). Alliums stunt legume growth.
- Tomatoes and brassicas (cabbage, broccoli, kale). Heavy nutrient competition and shared pests.
- Fennel and almost everything. Fennel is allelopathi
- Corn and tomatoes. Both attract the corn earwor
Look up any crop
Pick your main crop from the list (tomatoes, peppers, cucumbers, beans, carrots, lettuce, squash, onions, corn, or strawberries) and the guide returns the specific plants that boost it, the ones to keep apart, and practical planting tips. Free, no signup.
Frequently asked questions
Does companion planting really work?
Some pairings have strong scientific backing (the Three Sisters, pollinator draws, nitrogen fixation, allelopathy). Others sit in the “gardener folklore, plausible mechanism” category. Neither costs you anything to tr
What can I plant with tomatoes?
Basil, marigolds, carrots, parsley, chives, and borage. Avoid brassicas (cabbage, broccoli), fennel, and corn.
What is the Three Sisters garden?
An indigenous polyculture of corn, pole beans, and winter squash grown in the same mound. The corn supports the beans, the beans fix nitrogen, and the squash shades the soil and repels pests with its prickly leaves.
Which plants pair with what? Let’s get started…
