Onion

Allium cepa

Amaryllidaceae

Cabbage

Brassica oleracea var. capitata

Brassicaceae

Can you plant onions and cabbage together?

Yes. Onions and cabbage grow well together. A shared bed gave about 8% more harvest than separate beds in 5 field trials, and onions drew in insects that eat the pests of cabbage in a field trial.

Why onions and cabbage work together

More harvest from the same bed. In 5 field trials, a bed with both crops gave about 8% more harvest than the same space split into a cabbage bed and a onion bed.
Agronomic Performance of Collards under Two Intercrops and Varying Nitrogen Application Levels as Assessed Using Land Equivalent Ratios (Mutiga · 2011)
and 4 more sources
Draws in pest-eating insects. In a field trial, onions drew in insects that eat the pests of cabbage.
Management of Flea Beetles Using Ecological Engineering in Vegetable Agroecosystem of Kashmir (Maqsood S · 2024 · Research Square)
Fewer pests. In a greenhouse or pot trial, onions kept pests off cabbage.
Disturbance and competition drive diversity effects in cabbage-aphid-onion systems with intra-specific genetic variation. (Guilbaud CSE · 2020 · Bulletin of entomological research)
Garden charts recommend it. 2 garden chart entries recommend growing them together. Charts pass on gardening tradition; they are not tests.
Companion Plants (Alabama Cooperative Extension System)

What to plant with onions and cabbage

Good neighbours of both, best tested first.

BeetWith onions: 64% more harvestWith cabbage: 14% more harvest
DillWith onions: Draws in pest-eating insectsWith cabbage: 55% more harvest
TomatoWith onions: Better soil and nutrient uptakeWith cabbage: 34% more harvest
LeekWith onions: Recommended by garden charts, not testedWith cabbage: 16% more harvest
BroccoliWith onions: Recommended by garden charts, not testedWith cabbage: Lures pests away

All 6 plants that suit both, with the evidence

What to keep away from onions and cabbage

PeaWith onions: Garden charts advise against it, not tested
AsparagusWith onions: Garden charts advise against it, not tested

The evidence in detail

For readers who want to dig in: every chart entry, study and yield trial behind the answer above, with the numbers.

Tradition, research and yield trials

Tradition

Good

avoidgood

2 chart entries: 2 recommend, 0 advise against.

All entries cite a source.

Research

Good

avoidgood

3 papers found: 3 positive, 0 negative.

pest suppressionyield / land usenatural enemies

auto-classified not reviewed by a person

Yield trial

Good

0.56

0.77

Cabbage gains more. Partial LER is each crop's share of the yield it would give alone.

5 field trials. Published LERs lean high.

Good neighbours

What happens above and below ground

Each animation illustrates a mechanism a study reported for this pair. Pick a card to focus on it.

Everything at once.

What is going on (4)

Pick a card to spotlight its animation in the scene.

Onion CabbageOnion helps keep pests off Cabbage: its scent and plant chemistry confuse or repel the insects that would attack it.

Researchgreenhouse / pot trial x1

Disturbance and competition drive diversity effects in cabbage-aphid-onion systems with intra-specific genetic variation. (Guilbaud CSE · 2020 · Bulletin of entomological research)

Onion CabbageOnion attracts or shelters predators and parasitic wasps that eat the pests of Cabbage.

Researchfield trial x1

Management of Flea Beetles Using Ecological Engineering in Vegetable Agroecosystem of Kashmir (Maqsood S · 2024 · Research Square)

Onion CabbageGrown together, Onion and Cabbage gave more food from the same ground than apart.

Researchfield trial x1

Increasing Productivity with Intercropping Systems in Cabbage Production (Guvenc I · 2006 · Journal of sustainable agriculture)

Onion CabbageMedian land equivalent ratio 1.08 over 5 trials: growing them together gave 1.08 times the harvest of two separate plots of the same size.

Partial LERs (medians): Onion 0.56 + Cabbage 0.97. Range across treatments 1.07 to 1.20. Medians are taken separately, so the parts need not add up to the median LER. LER above 1 is biased upward by publication bias.

Yield trialfield trial x5

Agronomic Performance of Collards under Two Intercrops and Varying Nitrogen Application Levels as Assessed Using Land Equivalent Ratios (Mutiga · 2011)

Effect of Intercropping Collard with Beans or Onions on Aphid Populations and Yields of Collard Under High Altitude Conditions in Kenya (Saidi · 2008)

3 more sources

Intercropping based on cauliflower: More productive, profitable and highly sustainable (Yildirim · 2005)

Increasing Productivity with Intercropping Systems in Cabbage Production (Guvenc · 2006)

Agronomic performance and biological efficiency of kale intercropped with spice species (Alves De Araujo Hendges · 2019)

Tradition saysGood

2 gardening-lore entries. Lore is a starting point, not proof.

Companion Plants (Alabama Cooperative Extension System)

Companion plants for both onions and cabbage

Plants that are good neighbours of each. Biggest harvest gain first; each cell links to the evidence for that pair.

Plant	With onions	With cabbage
Beet	64% more harvest from the same spaceField trial, 1 study. Charts: recommend.Evidence for onions and beets	14% more harvest from the same spaceField trial, 5 studies. Charts: recommend.Evidence for cabbage and beets
Dill	Draws in pest-eating insectsField trial, 1 study. Charts: recommend.Evidence for onions and dill	Draws in pest-eating insects and lures pests away55% more harvest from the same spaceField trial, 3 studies. Charts: recommend.Evidence for cabbage and dill
Tomato	Better soil and nutrient uptake and bigger combined harvestMixed results on soil and nutrientsField trial, 7 studies. Charts: not listed.Evidence for onions and tomatoes	34% more harvest from the same spaceField trial, 4 studies. Charts: not listed.Evidence for cabbage and tomatoes
Leek	No trial foundSame family (Amaryllidaceae): shares pests and diseasesNot tested. Charts: recommend.Evidence for onions and leeks	16% more harvest from the same spaceField trial, 1 study. Charts: not listed.Evidence for cabbage and leeks
Broccoli	No trial foundNot tested. Charts: recommend.Evidence for onions and broccoli	Lures pests awaySame family (Brassicaceae): shares pests and diseasesField trial, 3 studies. Charts: not listed.Evidence for cabbage and broccoli
Cauliflower	Bigger combined harvestField trial, 1 study. Charts: not listed.Evidence for onions and cauliflower	No trial foundSame family (Brassicaceae): shares pests and diseasesNot tested. Charts: recommend.Evidence for cabbage and cauliflower

Harvest from the same space compares a bed with both crops against the same area split into single-crop beds, counting the harvest of both crops (the land equivalent ratio in yield trials).

The evidence, with sources

ResearchGood3 entries

Goodpest suppressiongreenhouse / pot trialauto-classified

Onion helps Cabbage
Disturbance and competition drive diversity effects in cabbage-aphid-onion systems with intra-specific genetic variation.
Disturbance and competition drive diversity effects in cabbage-aphid-onion systems with intra-specific genetic variation. (Guilbaud CSE · 2020 · Bulletin of entomological research)

Relevance 94% · effect confidence 52%
Goodyield / land usefield trialauto-classified

Increasing Productivity with Intercropping Systems in Cabbage Production
Increasing Productivity with Intercropping Systems in Cabbage Production (Guvenc I · 2006 · Journal of sustainable agriculture)

Relevance 97% · effect confidence 35%
Goodnatural enemiesfield trialauto-classified

Onion helps Cabbage
Management of Flea Beetles Using Ecological Engineering in Vegetable Agroecosystem of Kashmir
Management of Flea Beetles Using Ecological Engineering in Vegetable Agroecosystem of Kashmir (Maqsood S · 2024 · Research Square)

Relevance 85% · effect confidence 75%

Yield trialGood5 entries

GoodLER 1.08field trial

Kenya, 2006; Additive design; median LER 1.08 over 4 treatment(s)
Agronomic Performance of Collards under Two Intercrops and Varying Nitrogen Application Levels as Assessed Using Land Equivalent Ratios (Mutiga · 2011)
No effectLER 1.02field trial

Kenya, 1999-2000; Additive design; median LER 1.02 over 8 treatment(s)
Effect of Intercropping Collard with Beans or Onions on Aphid Populations and Yields of Collard Under High Altitude Conditions in Kenya (Saidi · 2008)
GoodLER 1.08field trial

Turkey, 2000-2002; Additive design; median LER 1.08 over 3 treatment(s) · partial LER Cabbage 0.97
Intercropping based on cauliflower: More productive, profitable and highly sustainable (Yildirim · 2005)

Show 2 more

GoodLER 1.17field trial

Turkey, 2000-2002; Additive design; median LER 1.17 over 3 treatment(s) · partial LER Cabbage 0.98, Onion 0.19
Increasing Productivity with Intercropping Systems in Cabbage Production (Guvenc · 2006)
GoodLER 1.28field trial

Brazil, 2015; Additive design; median LER 1.28 over 1 treatment(s) · partial LER Cabbage 0.36, Onion 0.92
Agronomic performance and biological efficiency of kale intercropped with spice species (Alves De Araujo Hendges · 2019)

TraditionGood2 entries

GoodOnion helps Cabbage
Cabbage: helped by onions
Companion Plants (Alabama Cooperative Extension System)
GoodOnion helps Cabbage
Onion: helps cabbage
Companion Plants (Alabama Cooperative Extension System)

Plan a bed with onions and cabbage

All neighbours of onion and of cabbage, or every pair at once in the companion planting chart.

Have you grown onions and cabbage together?

Tell other gardeners what happened: spacing, pests, harvest, or ask a question. Reader notes are not checked by us and do not change the verdicts on this page.