Companion Planting Chart

The Companion Planting Chart is a gardening reference tool covering companion planting chart, companion planting guide, what to plant together chart, vegetable companion planting chart. Use the chart below to look up values instantly. Printable and downloadable versions are available on this page.

Companion Planting Chart — Vegetables

Companion Planting Guide — Vegetables
Plant Good Companions Bad Companions Why — Benefit or Problem
TomatoesBasil, carrots, marigolds, parsley, asparagusFennel, cabbage family, brassicasBasil repels aphids and spider mites. Marigolds deter nematodes and whitefly. Fennel inhibits tomato growth.
BasilTomatoes, peppers, oreganoSageRepels aphids, whitefly, and mosquitoes near tomatoes and peppers. Sage inhibits basil's growth.
CarrotsTomatoes, lettuce, onions, chives, rosemaryDill (when mature), parsnipsTomatoes and chives improve carrot flavour. Mature dill stunts carrot growth.
Beans (pole and bush)Carrots, cucumbers, corn, squash, brassicasOnions, garlic, shallots, fennelBeans fix nitrogen in the soil — benefiting neighbouring plants. Alliums inhibit bean growth.
CornBeans, squash, peas, cucumbersTomatoesBeans fix nitrogen for corn. Squash shades soil reducing weeds. Together these are the Three Sisters companion planting system.
SquashCorn, beans, nasturtiums, marigoldsPotatoesNasturtiums attract aphids away from squash. Marigolds deter squash bugs.
LettuceCarrots, radishes, strawberries, chivesBroccoli (can be too competitive for space)Radishes loosen soil for lettuce roots. Chives deter aphids.
OnionsCarrots, beets, strawberries, chamomileBeans, peas, sage, asparagusOnions deter carrot fly. Beans and peas are inhibited by alliums.
PeppersBasil, carrots, tomatoesFennel, kohlrabiBasil repels aphids and improves pepper flavour.
CucumbersBeans, corn, peas, radishes, lettuceFennel, sage, strong aromatic herbsRadishes deter cucumber beetles. Beans improve soil nitrogen for cucumbers.
Cabbage family (brassicas)Celery, onions, hyssop, chamomile, marigoldsStrawberries, tomatoes, peppersHyssop and chamomile attract beneficial insects. Marigolds deter cabbage moths.
PotatoesBeans, cabbage, corn, horseradish, marigoldsTomatoes, squash, sunflowers, cucumbersHorseradish deters Colorado potato beetles. Tomatoes share blight diseases with potatoes.
SpinachStrawberries, peas, beans, celeryFennelPeas and beans shade spinach from heat. Peas fix nitrogen.
PeasCarrots, radishes, turnips, cucumbers, beansOnions, garlic, chives, gladioliPeas fix nitrogen. Alliums stunt pea growth.
RadishesLettuce, peas, cucumbers, carrotsHyssopRadishes loosen soil and deter cucumber beetles.
BeetsOnions, lettuce, cabbage, garlicPole beans (runner beans)Garlic deters aphids near beets. Pole beans and beets inhibit each other.
GarlicRoses, beets, tomatoes, chamomilePeas, beans, sage, parsleyGarlic deters aphids, Japanese beetles, and fungal diseases on roses and tomatoes.
MarigoldsAlmost all vegetables — universal companionNone commonly notedDeters aphids, whitefly, nematodes, and many soil pests. Attracts pollinators.
NasturtiumsSquash, cucumbers, tomatoes, brassicasNone commonly notedActs as a trap crop — aphids prefer nasturtiums over vegetables. Also attracts pollinators.
StrawberriesLettuce, spinach, beans, onions, thymeCabbage, broccoli, cauliflowerThyme deters worms. Cabbage family competes aggressively for nutrients.

Source: Traditional companion planting practices and research from Rodale Institute and Cornell University Extension

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The Three Sisters Companion Planting System

The Three Sisters is a centuries-old Indigenous North American companion planting system using corn, beans, and squash together — each plant provides mutual benefits that improve yield for all three.

  1. Corn grows tall first providing a vertical structure for bean vines to climb — eliminating the need for trellises or poles.
  2. Beans are nitrogen-fixing legumes — their root bacteria convert atmospheric nitrogen into a form that enriches the soil for the corn and squash which are heavy nitrogen feeders.
  3. Squash spreads along the ground and its large leaves shade the soil — conserving moisture, cooling the root zone, and suppressing weeds that would compete with all three plants.
  4. Together the Three Sisters provide a complete nutritional profile: corn for carbohydrates, beans for protein and amino acids, and squash for vitamins and minerals. Indigenous communities relied on this combination as a dietary staple.

Companion Planting — Flowers and Herbs

Beneficial Companion Flowers and Herbs for the Vegetable Garden
Plant Benefit Plant Near
Marigold (Tagetes)Deters aphids, nematodes, whitefly, and many soil pests. Attracts pollinators.Most vegetables — especially tomatoes, peppers, squash.
NasturtiumTrap crop that draws aphids and caterpillars away from vegetables. Attracts pollinators.Squash, cucumbers, brassicas, tomatoes.
BorageDeters tomato hornworm and cabbage worm. Attracts bees strongly.Tomatoes, squash, strawberries.
LavenderRepels fleas, moths, and whitefly. Attracts bees and butterflies.Brassicas, roses, herbs.
Dill (young plants)Attracts beneficial insects (lacewings, hoverflies, parasitic wasps) that prey on aphids.Brassicas, lettuce, onions. Keep away from carrots and tomatoes when mature.
ChamomileImproves growth and flavour of nearby plants. Attracts beneficial insects.Brassicas, onions, most vegetables.
SunflowersAttracts pollinators and predatory insects. Provides shade and windbreak for shorter plants.Cucumbers, corn, squash.
YarrowAttracts predatory insects that control aphids and caterpillars. Improves nearby plant health.Most garden plants.

Companion Planting Lookup

Enter a vegetable or herb to get its best companions, plants to avoid, and spacing guide. Filter by garden type or season.

26 results found

Tomatoes
Good companions

Basil, carrots, marigolds, parsley, asparagus

Avoid

Fennel, cabbage family, brassicas

Spacing

60–90 cm apart

Basil repels aphids and spider mites. Marigolds deter nematodes and whitefly. Fennel inhibits tomato growth.
Basil
Good companions

Tomatoes, peppers, oregano

Avoid

Sage

Spacing

20–30 cm apart

Repels aphids, whitefly, and mosquitoes near tomatoes and peppers. Sage inhibits basil's growth.
Carrots
Good companions

Tomatoes, lettuce, onions, chives, rosemary

Avoid

Dill (when mature), parsnips

Spacing

5–8 cm apart

Tomatoes and chives improve carrot flavour. Mature dill stunts carrot growth.
Beans
Good companions

Carrots, cucumbers, corn, squash, brassicas

Avoid

Onions, garlic, shallots, fennel

Spacing

15–20 cm apart

Beans fix nitrogen in the soil — benefiting neighbouring plants. Alliums inhibit bean growth.
Corn
Good companions

Beans, squash, peas, cucumbers

Avoid

Tomatoes

Spacing

30–35 cm apart

Beans fix nitrogen for corn. Squash shades soil reducing weeds. Together these are the Three Sisters companion planting system.
Squash
Good companions

Corn, beans, nasturtiums, marigolds

Avoid

Potatoes

Spacing

60–90 cm apart

Nasturtiums attract aphids away from squash. Marigolds deter squash bugs.
Lettuce
Good companions

Carrots, radishes, strawberries, chives

Avoid

Broccoli (can be too competitive for space)

Spacing

20–25 cm apart

Radishes loosen soil for lettuce roots. Chives deter aphids.
Onions
Good companions

Carrots, beets, strawberries, chamomile

Avoid

Beans, peas, sage, asparagus

Spacing

10–15 cm apart

Onions deter carrot fly. Beans and peas are inhibited by alliums.
Peppers
Good companions

Basil, carrots, tomatoes

Avoid

Fennel, kohlrabi

Spacing

45–60 cm apart

Basil repels aphids and improves pepper flavour.
Cucumbers
Good companions

Beans, corn, peas, radishes, lettuce

Avoid

Fennel, sage, strong aromatic herbs

Spacing

45–60 cm apart

Radishes deter cucumber beetles. Beans improve soil nitrogen for cucumbers.
Cabbage
Good companions

Celery, onions, hyssop, chamomile, marigolds

Avoid

Strawberries, tomatoes, peppers

Spacing

45–60 cm apart

Hyssop and chamomile attract beneficial insects. Marigolds deter cabbage moths.
Potatoes
Good companions

Beans, cabbage, corn, horseradish, marigolds

Avoid

Tomatoes, squash, sunflowers, cucumbers

Spacing

30–38 cm apart

Horseradish deters Colorado potato beetles. Tomatoes share blight diseases with potatoes.
Spinach
Good companions

Strawberries, peas, beans, celery

Avoid

Fennel

Spacing

15–20 cm apart

Peas and beans shade spinach from heat. Peas fix nitrogen.
Peas
Good companions

Carrots, radishes, turnips, cucumbers, beans

Avoid

Onions, garlic, chives, gladioli

Spacing

5–8 cm apart

Peas fix nitrogen. Alliums stunt pea growth.
Radishes
Good companions

Lettuce, peas, cucumbers, carrots

Avoid

Hyssop

Spacing

5–8 cm apart

Radishes loosen soil and deter cucumber beetles.
Beets
Good companions

Onions, lettuce, cabbage, garlic

Avoid

Pole beans (runner beans)

Spacing

10–15 cm apart

Garlic deters aphids near beets. Pole beans and beets inhibit each other.
Garlic
Good companions

Roses, beets, tomatoes, chamomile

Avoid

Peas, beans, sage, parsley

Spacing

15–20 cm apart

Garlic deters aphids, Japanese beetles, and fungal diseases on roses and tomatoes.
Marigolds
Good companions

Almost all vegetables — universal companion

Avoid

None commonly noted

Spacing

20–30 cm apart

Deters aphids, whitefly, nematodes, and many soil pests. Attracts pollinators.
Nasturtiums
Good companions

Squash, cucumbers, tomatoes, brassicas

Avoid

None commonly noted

Spacing

25–30 cm apart

Acts as a trap crop — aphids prefer nasturtiums over vegetables. Also attracts pollinators.
Strawberries
Good companions

Lettuce, spinach, beans, onions, thyme

Avoid

Cabbage, broccoli, cauliflower

Spacing

30–45 cm apart

Thyme deters worms. Cabbage family competes aggressively for nutrients.
Borage
Good companions

Tomatoes, squash, strawberries

Avoid

None commonly noted

Spacing

30–45 cm apart

Deters tomato hornworm and cabbage worm. Attracts bees strongly.
Lavender
Good companions

Brassicas, roses, herbs

Avoid

None commonly noted

Spacing

45–60 cm apart

Repels fleas, moths, and whitefly. Attracts bees and butterflies.
Dill
Good companions

Brassicas, lettuce, onions (young plants only)

Avoid

Carrots, tomatoes (when mature)

Spacing

20–30 cm apart

Attracts beneficial insects (lacewings, hoverflies, parasitic wasps) that prey on aphids. Mature dill inhibits carrots and tomatoes.
Chamomile
Good companions

Brassicas, onions, most vegetables

Avoid

None commonly noted

Spacing

20–30 cm apart

Improves growth and flavour of nearby plants. Attracts beneficial insects.
Sunflowers
Good companions

Cucumbers, corn, squash

Avoid

Potatoes

Spacing

45–60 cm apart

Attracts pollinators and predatory insects. Provides shade and windbreak for shorter plants.
Yarrow
Good companions

Most garden plants

Avoid

None commonly noted

Spacing

30–45 cm apart

Attracts predatory insects that control aphids and caterpillars. Improves nearby plant health.

Frequently Asked Questions

What is companion planting?
Companion planting is the practice of growing different plants in close proximity for mutual benefit — including pest deterrence, pollinator attraction, soil improvement, and space efficiency. It draws on centuries of agricultural tradition and is increasingly supported by ecological research.
Does companion planting actually work?
Research supports some companion planting combinations — particularly marigolds deterring nematodes, legumes fixing nitrogen for neighbouring plants, and aromatic herbs confusing or deterring specific insect pests. The effectiveness of many traditional combinations is less rigorously tested but consistent with logical principles of ecology.
Why should tomatoes and fennel not be planted together?
Fennel releases allelopathic chemicals through its roots and leaf litter that inhibit the growth of most nearby plants — including tomatoes, peppers, and beans. Plant fennel in an isolated area of the garden or in a pot.
What plants grow well with tomatoes?
Basil, marigolds, carrots, parsley, and asparagus are all good tomato companions. Basil repels aphids and spider mites while marigolds deter nematodes, whitefly, and many soil pests near the tomato root zone.
What is the Three Sisters companion planting?
The Three Sisters is an Indigenous North American companion planting system using corn, beans, and squash together. Corn provides structure for beans to climb, beans fix nitrogen for all three, and squash shades the soil to conserve moisture and suppress weeds.
What plants should not be planted together?
Keep tomatoes away from fennel, brassicas, and mature dill. Keep beans and peas away from onions, garlic, and chives. Keep potatoes away from tomatoes — they share the same late blight disease.
Do marigolds really keep pests away?
Yes — French marigolds (Tagetes patula) are among the best-researched companion plants. Studies confirm they produce thiophenes through their roots that repel soil nematodes and their scent deters aphids, whitefly, and some beetles when planted in sufficient density.
Can I plant herbs and vegetables together?
Yes — many herbs make excellent vegetable companions. Basil improves tomato growth and flavour, dill attracts beneficial predatory insects, chamomile improves the growth of many neighbouring plants, and aromatic herbs like rosemary and thyme deter many insect pests.