Sweet corn

Zea mays

Poaceae

Radish

Raphanus sativus

Brassicaceae

Can you plant corn and radishes together?

Yes. Corn and radishes grow well together. A shared bed gave about 40% more harvest than separate beds in one field trial. That rests on two studies, so treat it as a lead, not a rule.

Why corn and radishes work together

More harvest from the same bed. In one field trial, a bed with both crops gave about 40% more harvest than the same space split into a sweet corn bed and a radish bed.
Yield and nutrient uptake of winter maize (Zea mays) with vegetable intercropping (Choudhary · 2014)
No clear effect on plant chemistry. In a field trial, growing them together made no clear difference to plant chemistry.
Spring- and Fall-Seeded Radish Cover-Crop Effects on Weed Management in Corn (Gieske MF · 2016 · Weed Technology)

What to plant with corn and radishes

Good neighbours of both, best tested first.

PepperWith corn: 44% more harvestWith radishes: 69% more harvest
BeanWith corn: 43% more harvestWith radishes: 21% more harvest
Squash & pumpkinWith corn: 13% more harvestWith radishes: Recommended by garden charts, not tested
CucumberWith corn: Fewer pestsWith radishes: Recommended by garden charts, not tested

How each one was tested, with the evidence

What to keep away from corn and radishes

CeleryWith corn: Garden charts advise against it, not tested
CarrotWith radishes: 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

No chart mentions this pair.

Research

No effect

avoidgood

1 paper found: 0 positive, 0 negative, 1 no effect.

allelopathy

auto-classified not reviewed by a person

Yield trial

Good

0.79

0.62

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

1 field trial. 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 (2)

Pick a card to spotlight its animation in the scene.

Sweet corn Radish No clear effectStudies looked for allelopathy from Sweet corn to Radish and found no clear effect.

Radish Sweet corn No clear effectStudies looked for allelopathy from Radish to Sweet corn and found no clear effect.

Researchfield trial x1

Spring- and Fall-Seeded Radish Cover-Crop Effects on Weed Management in Corn (Gieske MF · 2016 · Weed Technology)

Sweet corn RadishMedian land equivalent ratio 1.40 over 1 trial: growing them together gave 1.40 times the harvest of two separate plots of the same size.

Partial LERs (medians): Sweet corn 0.79 + Radish 0.62. Range across treatments 1.37 to 1.43. 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 x1

Yield and nutrient uptake of winter maize (Zea mays) with vegetable intercropping (Choudhary · 2014)

Companion plants for both corn and radishes

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

Plant	With corn	With radishes
Pepper	Lures pests away, better soil and nutrient uptake and less disease44% more harvest from the same spaceField trial, 5 studies. Charts: not listed.Evidence for corn and peppers	69% more harvest from the same spaceField trial, 2 studies. Charts: not listed.Evidence for radishes and peppers
Bean	Draws in pest-eating insects, fewer pests and better soil and nutrient uptake43% more harvest from the same spaceField trial, 22 studies. Charts: recommend.Evidence for corn and beans	21% more harvest from the same spaceField trial, 1 study. Charts: recommend.Evidence for radishes and beans
Squash & pumpkin	13% more harvest from the same spaceField trial, 4 studies. Charts: recommend.Evidence for corn and squash	No trial foundNot tested. Charts: recommend.Evidence for radishes and squash
Cucumber	Fewer pestsField trial, 1 study. Charts: not listed.Evidence for corn and cucumbers	No trial foundNot tested. Charts: recommend.Evidence for radishes 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).

The evidence, with sources

ResearchNo effect1 entry

No effectallelopathyfield trialauto-classified

Spring- and Fall-Seeded Radish Cover-Crop Effects on Weed Management in Corn
Spring- and Fall-Seeded Radish Cover-Crop Effects on Weed Management in Corn (Gieske MF · 2016 · Weed Technology)

Relevance 84% · effect confidence 55%

Yield trialGood1 entry

GoodLER 1.40field trial

India, 2010-2011; NA design; median LER 1.40 over 2 treatment(s) · partial LER Sweet corn 0.785, Radish 0.62
Yield and nutrient uptake of winter maize (Zea mays) with vegetable intercropping (Choudhary · 2014)

Plan a bed with corn and radishes

All neighbours of sweet corn and of radish, or every pair at once in the companion planting chart.

Have you grown corn and radishes 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.