Tradition
Good
avoidgood
4 chart entries: 4 recommend, 0 advise against.
All entries cite a source.
Carrot
Daucus carota subsp. sativus
Apiaceae
Onion
Allium cepa
AmaryllidaceaeCan you plant carrots and onions together?
It depends. The sources disagree about carrots and onions. Results on pests were mixed in a field trial, while growing them together kept pests down in a field trial.
Why it depends
Mixed results on pests. In a field trial, results on pests were mixed.
Trap Crops in Onion to Reduce Onion Thrips1 and Iris Yellow Spot Virus (Buckland KR · 2017 · Southwestern Entomologist)Fewer pests. In a field trial, growing them together kept pests down.
Effect of mixed cropping on some insect pests of carrots and onions (Uvah III · 1984 · Entomologia Experimentalis et Applicata.)Garden charts recommend it. 4 garden chart entries recommend growing them together. Charts pass on gardening tradition; they are not tests.
Effect of intercropping on the population density of pests in some vegetables (Mateeva · 2002 · Acta Horticulturae)
What to plant with carrots and onions
Good neighbours of both, best tested first.
PepperWith carrots: 127% more harvestWith onions: 20% more harvest
LettuceWith carrots: 78% more harvestWith onions: Recommended by garden charts, not tested
CabbageWith carrots: 19% more harvestWith onions: 8% more harvest
CucumberWith carrots: Recommended by garden charts, not testedWith onions: Helpful plant chemistry
LeekRecommended by garden charts for both, not tested yet
What to keep away from carrots and onions
PeaWith carrots: Smaller combined harvestWith onions: Garden charts advise against it, not tested
ParsnipWith carrots: Garden charts advise against it, not tested
DillWith carrots: Garden charts advise against it, not tested
PotatoWith carrots: Garden charts advise against it, not tested
RadishWith carrots: 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
Research
Mixed
avoidgood
2 papers found: 1 positive, 0 negative, 1 mixed.
trap croppest suppression
auto-classified not reviewed by a person
Yield trial
No intercropping yield trial.
It's complicated
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.
Companion plants for both carrots and onions
Plants that are good neighbours of each. Biggest harvest gain first; each cell links to the evidence for that pair.
| Plant | With carrots | With onions |
|---|---|---|
| Pepper | 127% more harvest from the same spaceField trial, 1 study. Charts: not listed.Evidence for carrots and peppers | 20% more harvest from the same spaceField trial, 6 studies. Charts: recommend.Evidence for onions and peppers |
| Lettuce | 78% more harvest from the same spaceField trial, 1 study. Charts: recommend.Evidence for carrots and lettuce | No trial foundNot tested. Charts: recommend.Evidence for onions and lettuce |
| Cabbage | 19% more harvest from the same spaceField trial, 1 study. Charts: not listed.Evidence for carrots and cabbage | Fewer pests and draws in pest-eating insects8% more harvest from the same spaceField trial, 8 studies. Charts: recommend.Evidence for onions and cabbage |
| Cucumber | No trial foundNot tested. Charts: recommend.Evidence for carrots and cucumbers | Helpful plant chemistry and bigger combined harvestField trial, 3 studies. Charts: recommend.Evidence for onions and cucumbers |
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).
Recommended by garden charts for both, not tested yet
The evidence, with sources
- Mixedtrap cropfield trialauto-classifiedTrap Crops in Onion to Reduce Onion Thrips1 and Iris Yellow Spot VirusTrap Crops in Onion to Reduce Onion Thrips1 and Iris Yellow Spot Virus (Buckland KR · 2017 · Southwestern Entomologist)Relevance 86% · effect confidence 38%
- Goodpest suppressionfield trialauto-classifiedEffect of mixed cropping on some insect pests of carrots and onionsEffect of mixed cropping on some insect pests of carrots and onions (Uvah III · 1984 · Entomologia Experimentalis et Applicata.)Relevance 96% · effect confidence 91%
- GoodCarrot helps OnionCarrots: helps onionsEffect of intercropping on the population density of pests in some vegetables (Mateeva · 2002 · Acta Horticulturae)
- GoodOnion helps CarrotCarrots: helped by alliums (chives, leeks, onions, shallots, etc.)Effect of intercropping on the population density of pests in some vegetables (Mateeva · 2002 · Acta Horticulturae)
- GoodOnion helps CarrotOnion: helps carrotsEffect of intercropping on the population density of pests in some vegetables (Mateeva · 2002 · Acta Horticulturae)
- GoodCarrot helps OnionOnion: helped by CarrotsEffect of intercropping on the population density of pests in some vegetables (Mateeva · 2002 · Acta Horticulturae)
All neighbours of carrot and of onion, or every pair at once in the companion planting chart.
Have you grown carrots and onions together?
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