Last updated: July 16, 2026
The Vegetable Companion Planting Chart
The most productive vegetable gardens rarely grow in tidy, single-crop rows. They mix plants that genuinely help each other — legumes that feed their neighbours nitrogen, aromatic herbs that scramble the scent trails pests follow, tall corn that shades heat-sensitive squash. That is companion planting, and the relationships behind it are ecological, not folklore.
This chart covers 30 common vegetables: what to plant with each crop, what to keep it away from, and the mechanism that makes the pairing work. Understanding the “why” matters more than memorizing the grid — once you know that basil masks a tomato’s scent from aphids, you can swap in any strongly aromatic herb when basil runs short. Deep dives, a garden-layout plan, climate-by-climate adjustments, and a 30-second incompatibility guide follow below.
Growing herbs alongside your vegetables? The companion relationships shift once herbs enter the bed, so those get their own dedicated reference — linked prominently just below this chart.
| Vegetable Seeds | Plant With | Avoid Planting With | Why It Works |
|---|---|---|---|
| Tomatoes | Basil, carrots, marigolds, parsley, borage | Potatoes, fennel, corn, brassicas | Basil repels aphids & spider mites; marigolds suppress root-knot nematodes; carrots loosen soil around the roots |
| Peppers | Basil, carrots, onions, spinach, marigolds | Beans, fennel, kohlrabi | Basil improves fruit set and repels aphids; onions deter pepper weevils |
| Cucumbers | Beans, dill, radish, sunflowers, nasturtium | Potatoes, aromatic herbs (except dill), melons | Radish draws off cucumber beetles; dill pulls in beneficial insects; beans fix nitrogen |
| Corn | Beans, squash, pumpkin, cucumber, dill | Tomatoes, celery | The Three Sisters — beans fix nitrogen, squash shades out weeds, corn is a living trellis |
| Squash & Zucchini | Corn, beans, nasturtium, radish, borage | Potatoes, other squash (overcrowding) | Nasturtium is a trap crop for aphids & squash bugs; borage deters squash vine borer moths |
| Pumpkin | Corn, beans, nasturtium, marigolds | Potatoes, other winter squash | Large leaves shade soil and hold moisture; nasturtium and marigold cut squash-bug pressure |
| Beans (Bush & Pole) | Corn, cucumber, squash, carrots, strawberries | Onions, garlic, leeks, fennel, peppers | Fix atmospheric nitrogen into root nodules, feeding heavy-feeding neighbours |
| Peas | Carrots, spinach, turnips, radish, mint | Onions, garlic, leeks, fennel | Fix nitrogen; mint deters pea weevils; grow vertically without crowding low companions |
| Carrots | Tomatoes, peas, onions, leeks, rosemary, sage | Mature dill, fennel, parsnips | Onions and leeks mask carrots from carrot fly; deep roots aerate soil for shallow neighbours |
| Onions & Garlic | Carrots, beets, tomatoes, lettuce, chamomile | Beans, peas, asparagus, sage | Sulphur compounds repel a wide range of pests; chamomile is said to improve bulb growth |
| Leeks | Carrots, onions, celery, beets, lettuce | Beans, peas, lentils | Leek scent confuses carrot fly — the carrot-leek pairing is one of the best-documented in companion planting |
| Green Onions | Carrots, lettuce, brassicas, beets, strawberries | Beans, peas | Fast, shallow-rooted, and pungent — slot between slower crops as a living pest deterrent |
| Lettuce | Carrots, radish, strawberries, chives, tall crops | Celery, parsley (can stunt) | Thrives in light shade from taller crops; radish nearby acts as an aphid trap |
| Spinach | Strawberries, peas, onions, beans, corn | Fennel | Light shade from taller crops extends the season; peas feed it nitrogen |
| Arugula | Bush beans, beets, carrots, dill, nasturtium | Other brassicas (shared pests) | Nasturtium lures flea beetles away; fast harvest clears space before pests build up |
| Broccoli | Onions, beets, celery, dill, nasturtium | Tomatoes, peppers, strawberries, fennel | Dill draws wasps that parasitize cabbage worms; nasturtium traps aphids off the heads |
| Cauliflower | Onions, celery, beans, dill, nasturtium | Tomatoes, peppers, strawberries | Alliums repel cabbage moths; celery scent confuses egg-laying butterflies |
| Cabbage | Onions, celery, dill, chamomile, potatoes | Strawberries, tomatoes, peppers, grapes | Celery repels cabbage white butterflies; chamomile is thought to improve flavour |
| Kale | Beets, onions, potatoes, nasturtium, herbs | Beans, tomatoes, strawberries | Nasturtium pulls aphids and whitefly off the leaves; beets share bed space without competing |
| Eggplant | Peppers, beans, marigolds, thyme, tarragon | Fennel, corn | Marigolds deter flea beetles — eggplant’s number-one pest; beans supply nitrogen |
| Potatoes | Beans, corn, cabbage, marigolds, horseradish | Tomatoes, squash, cucumbers, sunflowers, fennel | Horseradish at the corners repels Colorado potato beetle; beans feed tuber growth |
| Beets | Kale, lettuce, onions, kohlrabi, garlic | Pole beans, mustard | Improve soil for following crops; garlic nearby deters beet aphid |
| Radish | Cucumbers, lettuce, peas, spinach, nasturtium | Hyssop, grapes | A natural trap crop — flea beetles and aphids prefer it to your main crop |
| Swiss Chard | Beans, peas, radish, onions, brassicas | Fennel | Tolerates light shade; beans fix nitrogen; deep roots leave room for shallow companions |
| Okra | Peppers, basil, sunflowers, cucumbers, melons | Nothing major — a generous neighbour | Tall stalks shelter tender crops from wind; flowers feed pollinators and beneficials |
| Celery | Tomatoes, beans, leeks, cauliflower, cabbage | Corn, aster-family plants | Strong scent confuses cabbage butterflies and many flying pests |
| Turnips | Peas, beans, onions, mint, nasturtium | Potatoes, other root brassicas | Peas feed nitrogen; aromatic mint and onions mask them from root maggots |
| Strawberries | Beans, spinach, lettuce, borage, onions | Brassicas, fennel | Borage boosts pollination and fruit set; beans feed the bed while berries establish |
| Herbs (General) | Nearly every vegetable benefits | Fennel (isolate from almost everything) | Aromatic oils confuse pests and pull in beneficials — fennel is the one exception |
Browse all vegetable seed categories →
Herbs follow a different set of rules — which ones guard which vegetables, which herbs clash with each other, and which should never share a bed. Our companion guide for herbs covers all of it.
Open the Herb Companion Planting Chart →How Companion Planting Works — the Science
Companion planting is not folklore dressed up as gardening advice. A handful of clear, repeatable mechanisms explain the best pairings, and knowing them lets you make your own smart decisions instead of leaning on a chart.
Nitrogen Fixation With Legumes
Beans, peas, and other legumes host Rhizobium bacteria in nodules on their roots. Those bacteria pull nitrogen straight from the air and convert it into a form plants can absorb, so legumes quietly fertilize the soil around them. Heavy feeders planted alongside — corn, tomatoes, peppers, brassicas — all benefit, and a bed that grew legumes one year gives the following crop a running start. The Three Sisters is the most famous expression of this, but the logic applies to any nitrogen-hungry neighbour. For the full picture on building fertility this way, our guide to cover crops and green manures carries the details.
Pest Confusion & Trap Cropping
Most pest insects find their host plants by scent, homing in on specific volatile compounds. Mix strongly aromatic herbs and flowers into a bed and you scramble those chemical signals — entomologists call it host-plant masking. Basil among tomatoes is the classic case; its oils interfere with how aphids and thrips navigate. Trap cropping works the opposite way: you plant something a pest finds irresistible nearby, and radish is the legend here — flea beetles and aphids swarm it first, sparing your cucumbers and lettuce. When companion planting alone can’t hold the line, our organic pest control guide covers row covers, beneficial insects, and safe sprays.
Allelopathy in the Garden
Allelopathy is when a plant releases chemicals that affect the plants around it — suppressing some, helping others. Fennel is the notorious vegetable-garden example: compounds from its roots and leaves stunt most vegetables and herbs, which is why it sits in the “avoid” column again and again. Keep it in its own bed or a pot. On the helpful side, sunflowers suppress weeds without harming most companions, and chamomile is thought to nudge the growth of onions and brassicas. The extreme case is black walnut, whose juglone kills tomatoes, peppers, and potatoes within a wide radius — if you garden near one, your choices in that zone are limited. If you want to grow fennel well while keeping it isolated, see our guide to growing fennel.
Pollinator Attraction & Yield
Cucumbers, squash, peppers, tomatoes, and beans all set more fruit when pollinators are on-site all day. A bed laced with flowering companions keeps bees and beneficial insects working from morning to evening. Borage earns its keep here — its blue star flowers are irresistible to bumblebees and it pairs beautifully with tomatoes, squash, and strawberries. Dill and cilantro left to flower call in parasitic wasps (Braconidae and Ichneumonidae) that hunt caterpillars and aphids. Our guide to designing a bee garden goes deeper on keeping pollinators in the vegetable patch.
Best Companion Planting Combinations That Really Work
A few combinations have earned legendary status because they deliver visible, repeatable results. Start with these.
Corn, beans, and squash — the most documented companion trio in North American history. Corn is the trellis, beans fix nitrogen, and squash leaves shade the soil, hold moisture, and smother weeds. Together they out-yield any of the three grown alone. Full method in our Three Sisters planting guide.
The garden’s dynamic duo. Basil’s volatile oils repel aphids, spider mites, and whiteflies, and many growers swear it sharpens tomato flavour. Plant basil 30–45 cm (12–18 in) from each tomato stem so both get full sun.
Ring broccoli, cabbage, kale, and cauliflower with alliums — onions, garlic, chives, leeks. Their sulphur compounds throw off cabbage white butterflies and cut looper-moth egg-laying. Add dill for parasitic wasps and you have a three-layer defense.
Lettuce, carrots, and radish is the most space-efficient trio in a small garden. Radish germinates fast and marks the rows, carrots root deep without crowding lettuce, and lettuce shades the soil to keep carrot roots cool.
The Three Sisters rewards a little planting discipline — the order and timing matter more than anything else. Here is the sequence that gives corn the head start it needs.
- Sow corn first, in blocks of at least 4 short rows (never a single row) so wind can pollinate the ears. Space hills about 30–45 cm (12–18 in) apart.
- Wait until the corn stands 15–20 cm (6–8 in) tall — tall enough to survive a climbing bean — before planting anything else.
- Sow 4–6 pole bean seeds in a ring around the base of each corn stalk. The stalk becomes their trellis; their roots feed the corn nitrogen.
- About a week later, plant squash or pumpkin seeds roughly 60–90 cm (2–3 ft) from the corn hills so the sprawling vines shade the open ground between plants.
- In a short season, stagger by two weeks and pick a corn variety under 70 days to maturity so all three finish before frost.
Companion Planting by Vegetable — Deep Dives
The chart gives you the quick answer. These deep dives give you the reasoning and the spacing for the crops gardeners search for most.
Tomatoes
Tomatoes are the most companion-planted vegetable in the world, and for good reason — aphids, spider mites, whiteflies, hornworms, and nematodes all target them, leaving companions plenty of work to do. Basil is the go-to, planted 30–45 cm (12–18 in) from each stem so both get sun. French marigolds around the bed perimeter release thiophene from their roots and suppress the nematodes that attack tomato roots, working best when left in place a full season. Carrots loosen the soil around the root zone, parsley draws in the wasps that parasitize hornworms, and borage repels hornworms while pulling in bees. Keep tomatoes away from potatoes (shared late blight), fennel (allelopathy), and brassicas (nutrient competition). Our complete guide to growing tomatoes covers planting, staking, and harvest.
Peppers
Peppers share most of the tomato playbook, unsurprisingly — they are close relatives. Basil is just as effective here, deterring aphids and thrips while improving fruit set. Onions and other alliums around the perimeter deter pepper weevils, one of the crop’s worst pests. Low leafy greens like spinach and lettuce make excellent ground-level companions: they don’t compete for vertical space, their shallow roots leave pepper roots undisturbed, and they keep the soil surface cool and moist. Marigolds at the edge handle nematodes. Our guide to growing peppers has the full starting and transplanting detail.
Cucumbers
Cucumbers are vigorous feeders that gain a lot from good neighbours. Radish is the standout — sown at the base of cucumber hills, it draws flea beetles and cucumber beetles away from the vines. Dill left to flower brings in parasitic wasps that target cucumber-beetle larvae, and beans nearby fix the nitrogen these hungry plants demand. Sunflowers trellised alongside act as a windbreak without crowding. Keep cucumbers away from potatoes, which share fungal diseases and compete for nutrients, and hold back on heavy aromatic herbs (dill excepted), which can suppress germination. See our guide to growing cucumbers for trellis and care options.
Squash & Zucchini
Squash is built for companion planting — its enormous leaves do the weed-suppression and moisture work for everything nearby. In a Three Sisters bed it is the ground-floor partner. Nasturtiums are the squash grower’s secret weapon, drawing aphids and squash bugs away as a decoy while pulling in predatory insects. Plant them generously at the bed edges and in the gaps. Borage nearby is thought to deter squash vine borer, the most destructive squash pest across eastern North America, and early radish deters squash beetles before the vines are large enough to shade them out. Our guide to growing zucchini has the full care detail.
Beans & Peas
Beans and peas are the nitrogen engines of the garden, and their value goes beyond the pairings in the chart. The core principle is simple: grow nitrogen-fixers next to nitrogen-hungry crops — corn, squash, tomatoes, peppers, and brassicas all benefit from the neighbourhood. The one firm rule is to keep beans and peas away from alliums; onions, garlic, leeks, and chives all inhibit the nitrogen-fixing bacteria in legume root nodules, and it is one of the best-supported incompatibilities in the research. Our guide to growing beans covers bush and pole types from sowing to harvest.
Brassicas: Broccoli, Cabbage, Kale & Cauliflower
Brassicas are the most pest-targeted family in the garden — cabbage worms, loopers, aphids, flea beetles, and root fly all hunt them — so companion planting earns its keep. Interplant the allium family generously; their sulphur compounds disrupt cabbage white butterflies and deter aphids. Dill left to flower calls in Braconid wasps that lay eggs inside caterpillars, the single most effective caterpillar control there is. Nasturtium works as the trap crop, gathering aphids and whiteflies on its own leaves instead of the heads, and celery interplanted repels the cabbage butterfly. Our guide to growing broccoli carries the crop-specific detail for the whole family.
Root Vegetables: Carrots, Beets & Radish
Root crops are excellent companions for the very reason they are easy to overlook — they grow underground. They don’t crowd the leaf canopy above, they loosen and aerate the soil, and many repel soil pests by scent. Carrots and leeks are the famous pair, each masking the other from its main pest, and onions do the same for carrots. Radish is the multitasker: it sprouts in 3–5 days, marks slow rows, breaks compaction for carrots beside it, and pulls flea beetles off the main crop. Our guide to growing carrots covers thinning and the deep, loose soil roots need.
Corn
Corn is one of the hungriest crops in the garden and will strip soil fertility fast as a monoculture — which is exactly why the Three Sisters is so elegant, with beans replacing the nitrogen corn removes. Corn’s height also makes it a natural trellis for climbing beans, and dill nearby brings in wasps that attack corn earworm. Cucumbers appreciate the partial shade of its canopy. The one warning: tomatoes and corn feed the same pest — corn earworm and tomato fruitworm are the same insect (Helicoverpa zea) — so pairing them amplifies pressure instead of easing it. Our guide to growing corn covers block spacing and pollination.
Onions, Garlic & Alliums
Alliums are the generalist defenders of the companion garden. Their sulphur-based compounds deter an extraordinary range of pests — aphids, carrot fly, cabbage worm, spider mites, and more. Garlic is the most potent, shown in multiple studies to knock back aphid numbers on nearby plants, and chives around roses and fruit trees deter aphids and some fungal issues. The single firm rule stands: keep every allium well away from beans and peas, where they sabotage nitrogen fixation. Our guide to growing onions from seed covers timing, which is everything with alliums.
Start your companion bed with open-pollinated, non-GMO seed. Jump straight to the crops in this chart:
Tomato seeds · Pepper seeds · Bean seeds · Cucumber seeds · Squash seeds · Carrot seeds · Lettuce seeds · Corn seeds · Herb seeds
What Not to Plant Together — the Worst Combinations
The “avoid” column deserves its own reference. These pairings consistently cause trouble — shared disease, stunted growth, nutrient competition, or amplified pests. Some are folk wisdom; several have solid research behind them.
| Don’t Plant Together | Why It Fails | What to Do Instead |
|---|---|---|
| 🍅 Tomatoes + Potatoes | Same family (Solanaceae), same diseases — late blight can wipe out both at once | Separate beds; rotate both out of that soil for at least 3 years |
| 🌿 Fennel + Almost Everything | Allelopathic compounds stunt tomatoes, peppers, beans, kohlrabi, and most herbs | Grow fennel alone in its own bed or a large container |
| 🧅 Onions/Garlic + Beans/Peas | Alliums inhibit the Rhizobium bacteria that let legumes fix nitrogen | Keep alliums and legumes in separate rows or beds |
| 🥔 Potatoes + Squash/Cucumbers | Heavy competition for moisture and nutrients, plus shared fungal disease | Space them into separate beds with good airflow |
| 🌽 Tomatoes + Corn | Both feed corn earworm / tomato fruitworm (Helicoverpa zea); corn also shades tomatoes | Plant at opposite ends of the garden |
| 🥦 Brassicas + Tomatoes/Peppers | All heavy feeders competing for calcium, phosphorus, and potassium | Rotate these families through separate beds |
| 🌼 Mature Dill + Carrots | Flowering dill cross-pollinates with carrots (both Apiaceae), degrading seed | Harvest dill before it flowers if it’s near carrots |
| 🌰 Black Walnut + Most Vegetables | Juglone from roots and leaves kills nightshades within 15–30 m (50–100 ft) | In that zone grow juglone-tolerant crops: beans, beets, corn, onions, squash |
How to Lay Out a Companion Planting Bed
Good companion planting is as much about layout as it is about which plants you choose — airflow, sun angle, and spacing decide whether the benefits actually show up. Crowding is the fastest way to trade a pest problem for a mildew problem, so plan for each plant’s mature size and leave room for air to move. A simple, repeatable structure works in a row garden or a raised bed alike.
- Put the tall heavy feeders — corn, staked tomatoes, sunflowers — on the north side of the bed so they don’t shade shorter crops (reverse this only in the low desert, where afternoon shade is welcome).
- Set a nitrogen-fixer (beans or peas) within about 1 m (3 ft) of each heavy feeder so the roots share the same soil zone.
- Ring the bed edges with flowering companions — marigolds, nasturtium, calendula, borage — to draw beneficial insects and act as trap crops.
- Tuck 2–3 aromatic herbs (basil, thyme, dill, chives) among the vegetables for scent-based pest cover.
- Keep at least 30 cm (12 in) of open space between mature plant groups — companions still need airflow, and dense planting invites blight and mildew.
One structural note for raised beds: the soil warms faster in spring, so you can transplant slow-to-establish companions like marigolds a couple of weeks earlier and get the full season of pest protection out of them. In a standard 1.2 m (4 ft) wide bed, run the tall crops down the centre or north edge and work outward to the low, quick companions.
Companion Planting by Climate — What Changes Where You Garden
The chart above is universal — the companion relationships hold everywhere. What changes by region is how you execute them: the timing, the spacing priorities, and which companions to lean on hardest. A gardener in Zone 3 and a gardener in the low desert use the same chart but make very different decisions. These three filters tell you how to adapt.
The constraint here is time and soil temperature. Standard advice assumes a 5–6 month window; you may have 90–120 days. Stagger the Three Sisters instead of planting all at once, and start marigolds and basil indoors 6–8 weeks early so they’re big enough to work by transplant time. Lead with cold-tolerant companions — peas, radish, onions, dill, chives — while the soil warms toward 16°C (61°F) for tomatoes and basil.
Here companion planting is about survival against fungal disease as much as nutrition. Choose open, upright companions — carrots, chives, leeks — around tomatoes rather than dense bush beans that trap stagnant, disease-friendly air. Root-knot nematode pressure is severe, so treat French marigolds as a permanent bed fixture, and succession-sow basil every 3–4 weeks since it bolts and loses potency fast in the heat.
In blazing, dry heat, companions are mostly about shade and moisture. Put tall structural plants — sunflowers, corn, staked pole beans — on the west or southwest side of heat-sensitive crops, where they cut afternoon soil temperature by 5–8°C (9–14°F). Maximize squash-leaf coverage to slow evaporation, and shift basil, dill, and cilantro to spring and fall — most aromatic herbs stall above 38°C (100°F).
❓ Vegetable Companion Planting FAQ
📚 Related Growing Guides
The herb-focused companion to this page — which herbs guard which crops, and which to keep apart.
Herb companion planting chart →The full corn-beans-squash method, spacing, and short-season timing.
Three Sisters planting guide →When companions aren’t enough — safe, effective options for every common pest.
Organic pest control guide →The most powerful companion flower in any vegetable garden — start to finish.
How to grow marigolds →Build soil, fix nitrogen, and suppress weeds between vegetable seasons.
Cover crops & ground cover guide →Complete guide from seed to harvest — varieties, staking, and pest management.
How to grow tomatoes →Design a garden that keeps pollinators on-site all season for better fruit set.
Bee garden & pollinator guide →When to start and transplant every crop by zone across the US and Canada.
North American planting calendar →
