Companion Planting Chart: 120+ Vegetables, Herbs & Flowers (2026)
Which plants help each other thrive — and which quietly sabotage their neighbors. This chart covers 66 vegetables, 27 herbs, and 25 flowers with full good-companion and avoid lists, the science behind why each pairing works, and timing notes by USDA zone.
Get Exact Planting Dates for Your Location
Companion planting timing depends on your frost dates. Enter your ZIP or city to see exactly when to plant each crop — and its companions — in your garden.
How Companion Planting Works
Companion planting isn't folklore — there are three well-documented mechanisms that explain most of the beneficial effects:
Aromatic pest confusion
Volatile compounds from herbs like basil, dill, and alliums (onion, garlic, chives) disrupt the chemical signals that pest insects use to locate host plants. Mixed plantings make it harder for aphids, carrot fly, and cabbage moth to zero in on their targets.
Nitrogen fixation
Legumes (beans, peas) host Rhizobium bacteria in their root nodules that convert atmospheric nitrogen into plant-available ammonium. This directly feeds neighboring heavy feeders like corn, squash, and brassicas — a natural alternative to synthetic fertilizer.
Beneficial insect habitat
Flowering companions (dill, fennel, marigolds, sweet alyssum) attract parasitic wasps, hoverflies, and lacewings whose larvae prey on aphids, caterpillars, and other pests. A few flowers in every vegetable bed can dramatically reduce pest pressure.
Realistic expectations: Companion planting reduces pest pressure and can improve yields — it doesn't eliminate pests entirely. Results are most consistent at the garden scale (under 1,000 sq ft) and when pairings are planted in close proximity (within 1–3 feet for aromatic benefits).
10 Best Companion Planting Combinations
The most impactful pairings — with the specific mechanism that makes each one work.
Basil repels aphids, spider mites, and whiteflies from tomatoes. Some growers report improved tomato flavor. Both thrive in the same warm, sunny conditions.
French marigolds (Tagetes patula) release a root chemical that repels root-knot nematodes — a major tomato pest. They also deter whiteflies and aphids above ground.
The classic Three Sisters pairing. Beans fix atmospheric nitrogen into the soil, directly feeding corn's heavy nutrient demand. Corn stalks give beans a trellis to climb.
Onion scent repels carrot fly; carrot scent repels onion fly. Each plant's aromatic compounds mask the host-finding cues of the other's main pest. Classic intercrop.
Radishes act as a trap crop, luring cucumber beetles away from cucumbers. Harvest radishes before they bolt and replant for ongoing protection throughout the season.
Dill attracts parasitic wasps (Ichneumonidae) that prey on cabbage worms and loopers — the primary pests of broccoli, cabbage, and kale. Let dill flower for best effect.
Garlic's sulfur compounds repel aphids, Japanese beetles, and fungal diseases. Plant at the base of roses in fall so it's established by the time roses leaf out.
Nasturtiums act as a sacrificial trap crop for aphids and squash bugs, keeping them off the squash. They also attract predatory insects and look beautiful sprawling through the bed.
Thyme's aromatic oils deter spider mites and thrips that attack strawberries. It also improves drainage in strawberry beds and attracts pollinators during strawberry bloom.
The Three Sisters: America's Original Companion Planting System
Developed by Indigenous peoples of North America over centuries, the Three Sisters — corn, beans, and squash — is one of the most studied and consistently effective companion planting systems in existence.
Tall stalks provide a natural trellis for beans to climb, eliminating the need for poles or cages.
Fixes atmospheric nitrogen via root bacteria, continuously feeding the corn and squash throughout the season.
Large leaves shade the soil, suppressing weeds and locking in moisture — less watering, less weeding.
Plant corn first, add beans when corn is 4–6" tall, and sow squash 1 week after beans emerge. Space corn hills 18" apart with 3–4 corn seeds per hill.
8 Plant Combinations to Avoid
These pairings actively harm one or both plants — keep them separated in your garden layout.
Tomato + Fennel
Fennel releases allelopathic chemicals that stunt tomato growth and reduce yields. Keep fennel at least 3 feet from any nightshade.
Tomato + Brassicas
Both are heavy feeders that compete intensely for nutrients. Brassicas can also harbor clubroot fungus that spreads to tomatoes.
Bean + Onion / Garlic
Alliums inhibit the nitrogen-fixing bacteria that live on bean roots, negating beans' main soil benefit and stunting bean growth.
Potato + Tomato
Both are nightshades that share the same fungal diseases (blight). Planting together concentrates the risk — one infected plant can spread to all.
Cucumber + Aromatic Herbs
Strong-scented herbs (sage, rosemary, basil in large amounts) can inhibit cucumber germination and slow growth of young seedlings.
Dill + Carrot
Dill and carrot are both Apiaceae family plants and will cross-pollinate, ruining seed stock. Mature dill also inhibits carrot growth.
Fennel + Almost Everything
Fennel is the one true loner of the vegetable garden. It releases allelopathic compounds that suppress the growth of most vegetables, especially tomatoes, peppers, and beans. Grow it in a container or isolated bed.
Potato + Squash / Pumpkin
Squash vines shade potato foliage needed for tuber development. Both are also susceptible to similar blights that spread easily between the two crops.
Vegetable Companion Planting Chart (A–Z)
66 vegetables. Click any plant name to see its full planting guide and companion details.
| Vegetable | Good Companions | Avoid |
|---|---|---|
| Acorn Squash | Corn, Bean, Marigold, Nasturtium | Potato |
| Arugula | Carrot, Lettuce, Radish, Bean | — |
| Asparagus | Tomato, Aster, Dill, Coriander, Parsley, Basil | Onion, Garlic, Potato |
| Banana Pepper | Basil, Carrot, Tomato, Marigold | Fennel, Brassicas |
| Beet | Lettuce, Onion, Brassicas, Kohlrabi | Pole bean, Field mustard |
| Bell Pepper | Tomato, Basil, Carrot, Onion, Parsley | Fennel, Kohlrabi, Brassicas |
| Bok Choy | Beet, Celery, Dill, Onion | Strawberry, Tomato |
| Broccoli | Beet, Celery, Onion, Potato, Dill | Tomato, Strawberry, Pepper |
| Broccoli Raab | Onion, Beet, Celery | Tomato, Pepper, Strawberry |
| Butternut Squash | Corn, Bean, Marigold, Nasturtium | Potato |
| Cabbage | Celery, Dill, Onion, Potato, Chamomile | Strawberry, Tomato, Grape |
| Cantaloupe | Corn, Sunflower, Marigold | Cucumber, Potato |
| Carrot | Onion, Leek, Lettuce, Tomato, Rosemary | Dill, Celery |
| Cauliflower | Beet, Celery, Bean, Onion | Strawberry, Tomato |
| Cayenne Pepper | Basil, Carrot, Tomato | Fennel |
| Celery | Cosmos, Daisy, SnapDragon | Corn, Aster |
| Chili Pepper | Basil, Rosemary, Oregano, Parsley, Marjoram, Tomato | Fennel |
| Collard Green | Beet, Celery, Onion, Dill | Tomato, Strawberry, Pepper |
| Common Bean | Corn, Squash, Carrot, Cucumber, Radish | Onion, Garlic, Fennel |
| Cucumber | Beans, Peas, Radish, Sunflower, Corn | Potato, Aromatic herbs, Melons |
| Edamame | Corn, Squash, Carrot | Onion, Garlic, Leek |
| Eggplant | Bean, Pepper, Spinach, Thyme | Fennel |
| Endive | Carrot, Radish, Lettuce | — |
| Fava Bean | Carrot, Potato, Beet, Spinach | Onion, Garlic, Fennel |
| Fennel | Dill | — |
| Garlic | Tomato, Pepper, Brassicas, Carrot, Rose | Bean, Pea, Asparagus |
| Grape Tomato | Basil, Carrot, Parsley, Marigold | Brassicas, Fennel, Corn |
| Green Bean | Corn, Squash, Carrot, Cucumber | Onion, Garlic, Fennel |
| Habanero Pepper | Basil, Carrot, Tomato | Fennel |
| Heirloom Tomato | Basil, Carrot, Parsley, Marigold, Borage | Brassicas, Fennel, Corn, Kohlrabi |
| Honeydew Melon | Corn, Sunflower, Marigold | Cucumber, Potato |
| Kale | Beet, Celery, Cucumber, Dill, Onion | Strawberry, Tomato |
| Kohlrabi | Beet, Onion, Cucumber, Herb | Tomato, Pepper, Strawberry |
| Leek | Celery, Apple, Carrot | Swiss Chard |
| Lima Bean | Corn, Squash, Cucumber, Carrot | Onion, Garlic, Fennel |
| Mâche | Radish, Carrot, Beet | — |
| Mizuna | Carrot, Onion, Beet, Spinach | Strawberry, Tomato |
| Mustard | Cabbage, Cauliflower, Radish, Brussel Sprout, Turnip | — |
| Napa Cabbage | Beet, Onion, Celery, Cucumber | Strawberry, Tomato, Pepper |
| Onion | Carrot, Beet, Lettuce, Tomato, Brassicas | Bean, Pea, Asparagus |
| Parsnip | Fruit Trees | — |
| Pea | Carrot, Radish, Turnip, Cucumber, Corn | Onion, Garlic |
| Poblano Pepper | Basil, Carrot, Tomato, Onion | Fennel |
| Pole Pea | Carrot, Radish, Turnip, Cucumber, Corn | Onion, Garlic |
| Popcorn | Bean, Squash, Cucumber | Tomato, Sweet Corn (cross-pollination) |
| Potato | Bean, Corn, Brassicas, Horseradish, Marigold | Tomato, Cucumber, Squash, Sunflower |
| Pumpkin | Corn, Bean, Marigold, Nasturtium | Potato |
| Radicchio | Carrot, Radish, Lettuce | — |
| Radish | Carrot, Lettuce, Pea, Cucumber, Spinach | Hyssop |
| Rutabaga | Onion, Garlic, Pea, Bean | Tomato, Pepper |
| Serrano Pepper | Basil, Carrot, Tomato | Fennel |
| Shishito Pepper | Basil, Carrot, Tomato, Marigold | Fennel, Brassicas |
| Snap Pea | Carrot, Radish, Lettuce, Spinach, Corn | Onion, Garlic |
| Snow Pea | Carrot, Radish, Lettuce, Corn, Turnip | Onion, Garlic |
| Sorrel | Strawberry, Carrot, Herb | Fennel |
| Spaghetti Squash | Corn, Bean, Marigold, Nasturtium | Potato |
| Spinach | Strawberry, Pea, Bean, Brassicas | — |
| Squash | Corn, Bean, Radish, Marigold | Potato |
| Sweet Corn | Bean, Squash, Cucumber, Pea, Melon | Tomato |
| Sweet Potato | Okra, Dill, Thyme | Squash, Sunflower |
| Swiss Chard | Beet, Onion, Bean, Cabbage | Leek, Corn |
| Tomatillo | Basil, Carrot, Marigold, Pepper | Fennel, Brassicas |
| Tomato | Basil, Carrot, Parsley, Marigold, Borage | Brassicas, Fennel, Corn, Kohlrabi |
| Watermelon | Corn, Sunflower, Marigold | Potato |
| Watermelon Radish | Carrot, Spinach, Lettuce, Pea | Hyssop |
| Zucchini | Corn, Beans, Nasturtium, Marigold | Potato |
Herb Companion Planting Chart (A–Z)
27 herbs. Most herbs are broadly beneficial — the key exceptions (sage vs. cucumber, mint spreading) are noted.
| Herb | Good Companions | Avoid |
|---|---|---|
| Anise | Coriander, Carrot | Fennel, Dill, Caraway |
| Basil | Tomato, Pepper, Oregano, Asparagus | Rue, Sage |
| Bee Balm | Tomato, Pepper, Squash | — |
| Borage | Tomato, Squash, Strawberry, Pepper | Fennel |
| Catnip | Tomato, Pepper, Squash, Pumpkin | — |
| Chamomile | Basil, Wheat, Onion, Cabbage, Cucumber | — |
| Chervil | Radish, Lettuce, Broccoli | — |
| Chives | Carrot, Tomato, Rose, Apple | Bean, Pea |
| Cilantro | Anise, Tomato, Spinach, Bean | Fennel |
| Dill | Cabbage, Onion, Lettuce, Cucumber | Carrot, Tomato |
| Ginger | Pepper, Eggplant, Tomato | — |
| Lavender | Tomato, Brassicas, Rose, Sage | — |
| Lemon Balm | Tomato, Squash, Bean, Pepper | — |
| Lemon Verbena | Basil, Tomato, Pepper | — |
| Lemongrass | Tomato, Basil, Pepper | — |
| Lovage | Carrot, Celery, Potato | — |
| Marjoram | Pepper, Tomato, Basil, Bean | — |
| Mint | Cabbage, Tomato, Pea | Parsley, Chamomile |
| Oregano | Pepper, Tomato, Basil | — |
| Parsley | Asparagus, Tomato, Corn, Rose | — |
| Rosemary | Bean, Cabbage, Carrot, Sage | — |
| Sage | Rosemary, Cabbage, Carrot, Tomato | Cucumber, Onion |
| Stevia | Pepper, Tomato, Basil | Fennel |
| Summer Savory | Bean, Onion, Garlic, Rosemary | Fennel |
| Tarragon | Eggplant | — |
| Thyme | Cabbage, Eggplant, Potato, Strawberry | — |
| Valerian | Vegetable Garden, Earthworm attractor | — |
Mint note: Mint is an excellent companion for cabbage and tomatoes but spreads aggressively. Plant it in a buried container (a pot with drainage holes sunk into the soil) to keep it contained.
Beneficial Flowers for the Vegetable Garden
These 25 flowers earn their place in any vegetable bed by attracting beneficials, repelling pests, or acting as trap crops.
French marigolds (Tagetes patula) are most effective. Plant densely around tomatoes and peppers.
Aphids prefer nasturtiums over most vegetables. Let them accumulate on nasturtiums, then remove infested plants.
Hoverfly larvae eat aphids. A single alyssum border plant can support dozens of beneficial hoverflies.
Borage is said to repel tomato hornworm and definitely attracts bumblebees during tomato bloom.
Long-blooming zinnias keep pollinators in the garden all season. Lacewings lay eggs in zinnia plantings.
Aphids colonize sunflower stems early in the season, distracting them from cucumbers and squash.
| Flower | Companion Benefits For | Avoid Near |
|---|---|---|
| Bachelor Button | Tomato, Bean, Vegetable Garden | — |
| Black-eyed Susan | Echinacea, Lavender, Sage, Switchgrass | — |
| Celosia | Marigold, Zinnia, Basil | — |
| Columbine | Fern, Hostas, Spring Bulbs | — |
| Cosmos | Corn, Squash, Tomato | — |
| Daffodil | Tulip, Crocus | — |
| Dahlia | Marigold, Basil, Cosmos | — |
| Echinacea (Coneflower) | Black-eyed Susan, Lavender, Sage | — |
| Hollyhock | Rose, Vegetable Garden | — |
| Impatiens | Begonia, Fern, Hostas | — |
| Larkspur | Cosmos, Zinnia, Rose | — |
| Lupine | Carrot, Brassicas, Corn | Fennel |
| Marigold | Tomato, Pepper, Basil, Squash | — |
| Morning Glory | Corn, Sunflower | — |
| Nasturtium | Tomato, Cucumber, Squash, Radish | Fennel |
| Pansy | Spring Bulbs, Vegetables | — |
| Petunia | Tomato, Basil, Marigold | Fennel |
| Salvia (Annual) | Tomato, Marigold, Basil | — |
| Snapdragon | Tomato, Vegetable Garden | — |
| Sunflower | Corn, Cucumber, Squash | Potato, Fennel |
| Sweet Alyssum | Tomato, Broccoli, Lettuce, Vegetable Garden | — |
| Sweet Pea | Carrot, Radish, Spinach | Onion, Garlic |
| Tulip | Daffodil, Grape Hyacinth | — |
| Verbena | Marigold, Petunia, Salvia | — |
| Zinnia | Tomato, Cucumber, Pepper | — |
Timing Companion Planting by Zone
The relationships between companion plants are the same in every zone — but the timing to establish those companions varies significantly:
Zones 9–13
Florida, South Texas, Hawaii
Marigolds and basil can be established 4–6 weeks before tomato transplants. Year-round gardening means companions can be maintained as a permanent border.
Zones 7–8
Mid-Atlantic, Pacific NW, Southeast
Start companion herbs indoors 6–8 weeks before last frost alongside tomatoes and peppers. Transplant companions at the same time as your main crops.
Zones 5–6
Midwest, New England, Great Plains
Cold springs mean companions and main crops often go in simultaneously. Use transplants (not seed-sown companions) for faster establishment before summer heat sets in.
Zones 3–4
Northern Minnesota, Maine, Mountain West
Short seasons demand efficiency. Stick to fast-establishing companions (radish, nasturtium from seed, marigold transplants) rather than slow-growing herbs. Row cover extends the season for both crops and companions.
Use the planting date tool to get exact sow/transplant dates for companion herbs and flowers at your ZIP code, or browse by zone or state.
Frequently Asked Questions
Does companion planting actually work? +
Yes, though the strength of effects varies. Well-documented mechanisms include: (1) aromatic herb and allium volatiles that disrupt pest host-finding; (2) legume nitrogen fixation that feeds neighboring plants; (3) flower plantings that attract beneficial predatory insects. The Three Sisters (corn, beans, squash) is backed by centuries of indigenous agricultural practice and modern yield studies. Results depend on scale, placement, and the specific pests in your garden.
How close do companion plants need to be? +
For aromatic pest repellents, plant companions within 1–3 feet of the host plant — volatile compounds dissipate quickly with distance. For nitrogen-fixing legumes, direct root contact is most effective, so interplant between rows. For beneficial insect attractors (dill, fennel, marigolds), plantings anywhere in the garden bed can help since insects forage broadly.
What is the Three Sisters planting method? +
The Three Sisters is an indigenous companion planting system using corn, beans, and squash together. Corn provides a vertical trellis for beans to climb. Beans fix nitrogen from the air into the soil, feeding the corn and squash. Squash's large leaves shade the soil, reducing weeds and retaining moisture. Together the three crops yield more per square foot than planted separately.
Why is fennel bad for most vegetables? +
Fennel produces allelopathic compounds (primarily anethole and other terpenoids) that are released from its roots and leaves into the surrounding soil and air. These chemicals inhibit germination and suppress growth in most vegetables, especially tomatoes, peppers, and beans. Grow fennel in a container or in an isolated bed at least 3–4 feet from your vegetable garden.
Can I use companion planting in raised beds? +
Yes — raised beds are ideal for companion planting because you control the soil and spacing precisely. The limited space actually makes placement more important: pair plants at the edges of beds where their root systems can interact without crowding, and use vertical companions (beans, cucumbers) on the north side so they don't shade smaller companions.
What flowers are most beneficial in a vegetable garden? +
Marigolds (French, not African), nasturtiums, sweet alyssum, and borage are the most broadly useful. Marigolds deter nematodes and aphids. Nasturtiums are excellent trap crops for aphids and squash bugs. Sweet alyssum attracts hoverflies whose larvae eat aphids. Borage repels tomato hornworm and attracts pollinators. Plant a border of these around any vegetable bed.
Do companion plants work the same in all USDA zones? +
The plant relationships themselves are consistent across zones, but timing is zone-dependent. In Zone 9–10, you can establish marigold borders before nightshades are planted. In Zone 5–6, frost dates mean both the companion and the main crop go in around the same time. Use the planting calendar tool on this site to sync your companion planting schedule with your exact frost dates.
Know What to Plant — Know When to Plant It
This chart tells you what grows well together. The planting calendar tells you exactly when to put each companion in the ground at your location.