Companion-planting table
All 45 species — which thrive together and which harm one another.
Bioterra · Residence of Action and Meaning
Two absolute rules
- Fennel keep isolated from everything: it inhibits nearly every crop.
- Mint must be grown in a pot: it takes over the whole garden in two years.
No result.
| Species | Plant together | Keep apart | Why |
|---|---|---|---|
| Garlic Allium sativum | Tomato Carrot Roses (fungicide) Strawberry Lettuce | Legumes Cabbages (the family) Fennel | Garlic interplanted among tomatoes acts as a powerful natural fungicide against blight Legumes (bean, broad bean, pea) — a strong antagonism; never pair them |
| Aubergine Solanum melongena | Basil ★ French marigold Savory | Fennel Potato Broad beans | Under glass, can share space with pepper — the same heat needs Broad beans release compounds that hold back the nightshade family |
| Basil ★ Ocimum basilicum | Tomato Pepper Cucumber (greenhouse) Lettuce | Thyme, rosemary & sage Fennel Thyme, rosemary & sage | The perfect tomato companion — repels thrips, aphids and whiteflies Sage and basil — their essential oils compete chemically and cancel each other out |
| Beetroot Beta vulgaris | Lettuce Cabbages (the family) Onion Nasturtium Dwarf bean | Fennel Bean | Beetroot enriches the soil with minerals that benefit neighbouring brassicas Climbing bean stunts beetroot — a proven antagonism Dwarf bean is fine; climbing bean is not |
| Nasturtium Tropaeolum majus | Cabbages (the family) Tomato Courgette Almost everything | The universal sacrificial plant — it draws aphids away from the vegetables. Aphids prefer nasturtium Repels whiteflies from tomatoes. Plant as an edging around every zone | |
| Carrot Daucus carota | Leek Onion Thyme, rosemary & sage Thyme, rosemary & sage Tomato Peas | Coriander & dill (when mature) Fennel | Carrot and leek, the classic pest-deterring duo: carrot fly and leek moth repel one another Young dill is fine; flowering dill inhibits carrot. Keep an eye on it |
| Celery Apium graveolens | Tomato Cabbages (the family) Leek Onion | Fennel Carrot (same family) | Its scent repels carrot fly and cabbage aphids Same family as carrot (Apiaceae) — same pests; do not pair |
| Cabbages (the family) Brassica oleracea | Nasturtium (sacrificial) French marigold Thyme, rosemary & sage Celery Beetroot Coriander & dill | Tomato Fennel Garlic Onion Savory | Cabbage guild: nasturtium draws aphids, thyme repels the cabbage white Tomato and cabbage — fierce competition for nutrients and shared diseases Fine-mesh insect netting is essential protection against cabbage white |
| Cucumber Cucumis sativus | Coriander & dill French marigold Onion Lettuce | Thyme, rosemary & sage Thyme, rosemary & sage Fennel Tomato (under glass) | Dill repels red spider mites, common under glass Sage and rosemary slow cucumber growth Under glass, keep tomato and cucumber apart — different humidity needs |
| Coriander & dill Coriandrum / Anethum | Cucumber (dill) Cabbages (the family) (dill) Peas (coriander) Lettuce | Carrot (mature dill) Fennel | Young dill is a good neighbour to carrot; flowering dill inhibits it. Watch for bolting Flowering dill attracts hoverflies and parasitoid wasps — let a few plants bolt |
| Squash & pumpkin Cucurbita maxima | Sweetcorn Bean Sunflower Nasturtium | Fennel Potato | Sunflower — a natural support that also draws pollinators to set the squash Squash covers the ground — an excellent living mulch that suppresses weeds |
| Courgette Cucurbita pepo | Sweetcorn Bean Nasturtium French marigold Onion | Fennel Potato | The Three Sisters trio, with corn and bean — a perfectly self-sustaining system Nasturtium draws aphids away from courgettes — a sacrificial plant |
| Spinach Spinacia oleracea | Strawberry Lettuce Onion Chives | Fennel Cabbages (the family) (competes for nitrogen) | Spinach and strawberry — a classic combination; they complement each other without competing A short-season plant — it clears out before its taller neighbours need the room |
| Fennel Foeniculum vulgare | Tomato Cabbages (the family) Bean Peas Lettuce Almost everything | Releases an allelopathic compound that inhibits the germination and growth of most crops Absolute BRAS rule: fennel in an isolated zone in the SW corner, with a physical barrier | |
| Broad beans Vicia faba | Carrot Lettuce Savory Cabbages (the family) (as a follow-on) | Onion Garlic Fennel Aubergine | Savory, the "bean herb" — repels the characteristic blackfly Pinching out the flowering tips stops blackfly before an infestation |
| Strawberry Fragaria × ananassa | Spinach Chives Thyme, rosemary & sage Thyme, rosemary & sage Garlic Parsley | Fennel Cabbages (the family) Mint (invasive) | Chives as an edging repel aphids and strawberry mites Mint in open ground would overrun the strawberries — pots only |
| Bean Phaseolus vulgaris | Sweetcorn Squash & pumpkin Savory French marigold Carrot | Onion Garlic Fennel Beetroot (climbing) | Climbing bean up corn is the ideal pairing. It fixes nitrogen for the corn Onion and garlic secrete compounds that inhibit legumes — a proven effect |
| Lettuce Lactuca sativa | Carrot Tomato (as ground cover) Onion Chives Nasturtium Beetroot | Fennel Garlic (in excess) | Lettuce under tomato is perfect: the light shade is welcome in summer and the soil stays covered The linchpin of zone 2 — it pairs with almost everything |
| Sweetcorn Zea mays saccharata | Bean Courgette Squash & pumpkin Sunflower | Fennel Tomato Cabbages (the family) | The Three Sisters trio: the bean fixes the nitrogen the corn devours Tomato — competes for the same nutrients and they shade one another |
| Mint Mentha spp. | Cabbages (the family) (repels cabbage white) Peas Tomato | The whole garden | Absolute BRAS rule: mint ALWAYS in a pot — its runners take over everything in 2 years In a pot: an excellent general repellent. Place near what you want to protect |
| French marigold Tagetes patula | Tomato Potato Courgette The whole garden | The roots secrete compounds that kill soil nematodes — the effect lasts 3 years Flowers draw pollinators to the whole area. Plant everywhere, without exception | |
| Onion Allium cepa | Carrot Tomato Beetroot Lettuce Courgette | Legumes Fennel Cabbages (the family) (competition) | An excellent all-round ally — its scent repels many pests Legumes — a confirmed chemical antagonism. Keep them firmly apart in the garden |
| Peas Pisum sativum | Carrot Radish (row marker) Lettuce Mint | Onion Garlic Leek Fennel | Alliums (onion, garlic, leek) strongly antagonise all legumes Peas fix nitrogen — an excellent precursor for hungry crops |
| Leek Allium ampeloprasum | Carrot Celery Tomato Thyme, rosemary & sage Thyme, rosemary & sage | Fennel Broad beans Peas | Carrot and leek — the classic pairing, the most effective against flies Legumes (broad beans, peas) are chemically antagonistic to alliums |
| Pepper Capsicum annuum | Basil ★ Carrot Onion French marigold | Fennel Cabbages (the family) Potato | Same guild as tomato — the same allies Can share the greenhouse with aubergine — same family, identical conditions |
| Potato Solanum tuberosum | Horseradish (as an edging) French marigold Savory Thyme, rosemary & sage | Tomato Squash & pumpkin Fennel Onion Cucumber | Tomato and potato — same family (nightshades); blight spreads instantly between them French marigold repels the nematodes that attack tubers Isolate in zone 3G — away from the tomatoes in zone 3C |
| Radish Raphanus sativus | Carrot (row marker) Lettuce Tomato Peas Nasturtium | Fennel Cabbages (the family) (same pests) | Radish between carrot rows: its quick germination marks the slow rows Radish left to go to seed traps flea beetles and protects the other brassicas |
| Rocket ★ Eruca vesicaria | Lettuce Parsley Basil ★ Nasturtium Onion | Fennel | An undemanding plant — a good neighbour to almost anything on the terrace Letting a few plants go to seed attracts ladybirds, which prey on aphids |
| Savory Satureja hortensis | Bean Broad beans Potato Cabbages (the family) | Fennel Cabbages (the family) (in excess) | The bean herb — repels the specific blackfly. Always plant it as an edging |
| Thyme, rosemary & sage Thymus / Rosmarinus | Cabbages (the family) Carrot Leek Tomato (rosemary) | Basil ★ (sage) Cucumber (sage + rosemary) Fennel | Mediterranean perennials: they draw bees and hoverflies for general pollination A herb guild edging zone 2 — its scent benefits the whole garden |
| Tomato Solanum lycopersicum | Basil ★ French marigold Garlic Lettuce Carrot Parsley | Cabbages (the family) (same family) Fennel Potato Dwarf bean | Basil repels aphids and whiteflies — a proven effect Cabbage competes at the roots and shares diseases Potato — same family (nightshades), same diseases |
| Sunflower Helianthus annuus | Squash & pumpkin Sweetcorn Bean Cucumber | Potato Fennel | A natural support for climbing beans. Draws pollinators and ladybirds The roots release mild allelopathic compounds — keep 50 cm from sensitive vegetables |