Garlic

Allium sativum

Amaryllidaceae

Pepper

Capsicum annuum

Solanaceae

Can you plant garlic and peppers together?

It depends. The sources disagree about garlic and peppers. Results on soil and nutrients were mixed in a field trial, while results on plant chemistry were mixed in a greenhouse or pot trial.

Why it depends

Mixed results on soil and nutrients. In a field trial, results on soil and nutrients were mixed.
Influence of Companion Planting on Microbial Compositions and Their Symbiotic Network in Pepper Continuous Cropping Soil. (Gao J · 2023 · Journal of microbiology and biotechnology)
Mixed results on plant chemistry. In a greenhouse or pot trial, results on plant chemistry were mixed.
Garlic exerts allelopathic effects on pepper physiology in a hydroponic co-culture system. (Ding H · 2016 · Biology open)
More harvest from the same bed. In one field trial, a bed with both crops gave about 55% more harvest than the same space split into a garlic bed and a pepper bed.
Yield and economics of chilli based intercropping system (Suresha · 2007)

What to plant with garlic and peppers

Good neighbours of both, best tested first.

Sweet cornWith garlic: 33% more harvestWith peppers: 44% more harvest
EggplantWith garlic: 25% more harvestWith peppers: Recommended by garden charts, not tested
CeleryWith garlic: Recommended by garden charts, not testedWith peppers: Better soil and nutrient uptake

How each one was tested, with the evidence

What to keep away from garlic and peppers

AsparagusWith garlic: Garden charts advise against it, not tested
KaleWith peppers: Garden charts advise against it, not tested
Brussels sproutsWith peppers: 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

Mixed

avoidgood

2 papers found: 0 positive, 0 negative, 2 mixed.

nutrients / soilallelopathy

auto-classified not reviewed by a person

Yield trial

Good

0.64

0.91

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

1 field trial. Published LERs lean high.

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.

What is going on (3)

Pick a card to spotlight its animation in the scene.

Garlic PepperStudies disagree. At best, garlic changes the soil for Pepper, sharing nutrients or feeding the fungal threads that link their roots.

Researchfield trial x1

Influence of Companion Planting on Microbial Compositions and Their Symbiotic Network in Pepper Continuous Cropping Soil. (Gao J · 2023 · Journal of microbiology and biotechnology)

Garlic PepperStudies disagree. At best, garlic releases root chemicals that benefit Pepper.

Researchgreenhouse / pot trial x1

Garlic exerts allelopathic effects on pepper physiology in a hydroponic co-culture system. (Ding H · 2016 · Biology open)

Garlic PepperMedian land equivalent ratio 1.55 over 1 trial: growing them together gave 1.55 times the harvest of two separate plots of the same size.

Partial LERs (medians): Garlic 0.64 + Pepper 0.91. Range across treatments 1.55 to 1.55. 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 economics of chilli based intercropping system (Suresha · 2007)

Companion plants for both garlic and peppers

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

Plant	With garlic	With peppers
Sweet corn	33% more harvest from the same spaceField trial, 2 studies. Charts: not listed.Evidence for garlic and corn	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 peppers and corn
Eggplant	Fewer pests and better soil and nutrient uptake25% more harvest from the same spaceField trial, 3 studies. Charts: not listed.Evidence for garlic and eggplant	No trial foundSame family (Solanaceae): shares pests and diseasesNot tested. Charts: recommend.Evidence for peppers and eggplant
Celery	No trial foundNot tested. Charts: recommend.Evidence for garlic and celery	Better soil and nutrient uptakeField trial, 1 study. Charts: not listed.Evidence for peppers and celery

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

ResearchMixed2 entries

Mixednutrients / soilfield trialauto-classified

Influence of Companion Planting on Microbial Compositions and Their Symbiotic Network in Pepper Continuous Cropping Soil.
Influence of Companion Planting on Microbial Compositions and Their Symbiotic Network in Pepper Continuous Cropping Soil. (Gao J · 2023 · Journal of microbiology and biotechnology)

Relevance 89% · effect confidence 17%
Mixedallelopathygreenhouse / pot trialauto-classified

Garlic exerts allelopathic effects on pepper physiology in a hydroponic co-culture system.
Garlic exerts allelopathic effects on pepper physiology in a hydroponic co-culture system. (Ding H · 2016 · Biology open)

Relevance 91% · effect confidence 73%

Yield trialGood1 entry

GoodLER 1.55field trial

India, 2005-2006; Additive design; median LER 1.55 over 1 treatment(s) · partial LER Garlic 0.64, Pepper 0.91
Yield and economics of chilli based intercropping system (Suresha · 2007)

Plan a bed with garlic and peppers

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

Have you grown garlic and peppers 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.