Companion planting is the practice of growing certain crops near each other to improve growth, deter pests, or enhance flavor. Some combinations have been used by gardeners for centuries — like the Native American "Three Sisters" of corn, beans, and squash.
Quick Reference Chart
| Crop | Good Companions | Keep Apart |
|---|---|---|
| Tomatoes | Basil, carrots, marigolds, parsley | Brassicas, fennel, dill |
| Peppers | Basil, spinach, tomatoes, carrots | Fennel, kohlrabi |
| Cucumbers | Beans, corn, peas, radishes, sunflowers | Potatoes, aromatic herbs |
| Carrots | Lettuce, onions, peas, tomatoes, rosemary | Dill, parsnips |
| Beans | Corn, squash, cucumbers, carrots | Onions, garlic, chives |
| Squash | Corn, beans (Three Sisters), marigolds | Potatoes |
| Lettuce | Carrots, radishes, strawberries, chives | Celery, parsley |
| Onions | Beets, carrots, lettuce, tomatoes | Beans, peas, asparagus |
| Broccoli | Beets, celery, onions, potatoes | Tomatoes, strawberries |
| Corn | Beans, squash, peas, cucumbers | Tomatoes, celery |
Why Companion Planting Works
Companion planting works through several mechanisms: pest confusion (strong-smelling herbs mask the scent of target crops), trap cropping (sacrificial plants lure pests away), nitrogen fixation (legumes feed neighboring plants), and pollinator attraction (flowers draw beneficial insects to your vegetable beds).
The Three Sisters Method
The most famous companion planting technique: plant corn as a vertical support, beans climb the corn stalks and fix nitrogen in the soil, and squash spreads at the base to shade the ground, retain moisture, and deter pests with its prickly leaves.
Best Companion Herbs
- Basil — Repels aphids and whiteflies; improves tomato flavor.
- Marigolds — Release a substance that deters root-knot nematodes; repel many flying pests.
- Rosemary — Deters carrot fly and cabbage moth.
- Chives — Repel aphids from roses and tomatoes; deter Japanese beetles.
- Dill — Attracts ladybugs and lacewings (aphid predators), but keep away from tomatoes.
Plan Your Companions
Use our free garden planner to lay out companion groups in your raised beds. The raised bed guide covers spacing and soil, and the seed starting guide will help you time everything perfectly.