Companion Planting Planner
Choose the vegetables, herbs, and flowers you’re growing and see instantly which pairings help each other — and which to keep apart. Every match comes with the reason behind it.
Pick Your Crops
Your pairings will appear here
Pick at least one crop to see its friends and foes — or start from a classic combination.
Why Companion Planting Works
Pest Confusion & Trap Crops
Strong-scented plants like alliums and aromatic herbs mask the smell of nearby crops from pests hunting by scent, while trap crops like nasturtiums lure aphids and squash bugs away from your vegetables.
Beneficial Insects
Flowering companions like dill, calendula, and sweet alyssum feed hoverflies, ladybugs, and parasitic wasps — predators whose larvae devour aphids, cabbage worms, and other pests. More flowers, more allies.
Soil, Shade & Structure
Legumes fix nitrogen for hungry neighbors, deep roots break soil for shallow ones, tall crops shade heat-sensitive greens, and sprawling vines act as living mulch — the logic behind the Three Sisters.
How It Works
Pick Your Crops
Select the vegetables, herbs, and flowers you’re planning to grow from the crop library — or search for them by name.
See Friends & Foes
Instantly see which of your crops help each other and which combinations to keep apart — with the reason behind every pairing.
Improve Your Plan
Add suggested companions that work with everything you’ve picked, resolve conflicts, and save your bed plan for planting time.
Frequently Asked Questions
Companion planting is the practice of growing certain plants near each other for mutual benefit — deterring pests, attracting pollinators and beneficial insects, fixing nitrogen, providing shade or support, or making better use of space. The most famous example is the Three Sisters: corn, beans, and squash grown together.
Some of it is well supported by research: French marigolds really do suppress root-knot nematodes, trap crops like nasturtiums measurably draw pests away, flowering herbs genuinely attract predatory insects, and legumes fix nitrogen. Other pairings — like basil improving tomato flavor — are gardening tradition with weaker evidence. Our tool notes the reason for each pairing so you can judge for yourself.
The Three Sisters is a Native American planting method combining corn, pole beans, and squash. Corn provides a natural trellis for the beans, beans fix nitrogen in the soil for the hungry corn, and squash spreads across the ground as a living mulch — shading out weeds, conserving moisture, and deterring animals with its prickly vines.
Keep tomatoes away from potatoes (both are nightshades that share blight), corn (corn earworm and tomato fruitworm are the same moth), the cabbage family (heavy competition), fennel (allelopathic), and mature dill. Good neighbors include basil, marigolds, carrots, onions, lettuce, and borage.
Onions, garlic, leeks, and chives release sulfur compounds from their roots that are traditionally said to inhibit the rhizobium bacteria legumes rely on to fix nitrogen, stunting beans and peas. It’s one of the most consistently repeated rules across traditional companion planting charts.
There’s no exact science, but a practical rule is to keep incompatible crops in separate beds, or at least 3–4 feet (about 1 meter) apart with another crop between them. For disease-sharing pairs like tomatoes and potatoes, more distance is better — and avoid planting one where the other grew last year.