Tomato

Solanum lycopersicum

Solanaceae

Potato

Solanum tuberosum

Solanaceae

Can you plant tomatoes and potatoes together?

Yes. Garden charts say to keep potatoes away from tomatoes, but the tests we found say otherwise. A shared bed gave about 112% more harvest than separate beds in one field trial. That rests on a single study, so treat it as a lead, not a rule.

Why the tests and the charts disagree

More harvest from the same bed. In one field trial, a bed with both crops gave about 112% more harvest than the same space split into a potato bed and a tomato bed.
Phosphite alters the behavioral response of potato tuber moth (Phthorimaea operculella) to field-grown potato (Mulugeta · 2019)
Garden charts advise against it. 2 garden chart entries say to keep them apart. None of them cites a source. Charts pass on gardening tradition; they are not tests.
List of companion plants (uncited entry) (Wikipedia)
Same family, shared pests. Potatoes and tomatoes are both in the Solanaceae family, so the same pests and diseases can move from one to the other.
Crop Rotation in the Vegetable Garden (Steil · 2025 · Iowa State University Extension and Outreach, Yard and Garden)

What to plant with tomatoes and potatoes

Good neighbours of both, best tested first.

BroccoliWith tomatoes: Recommended by garden charts, not testedWith potatoes: Bigger combined harvest
GarlicRecommended by garden charts for both, not tested yet
ThymeRecommended by garden charts for both, not tested yet

How each one was tested, with the evidence

What to keep away from tomatoes and potatoes

RosemaryWith tomatoes: Garden charts advise against it, not tested
CarrotWith potatoes: Garden charts advise against it, not tested
CucumberWith potatoes: Garden charts advise against it, not tested
Squash & pumpkinWith potatoes: Garden charts advise against it, not tested
AsparagusWith potatoes: 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

Same family, shared pests and diseases. Both in Solanaceae: often susceptible to the same diseases and insects. Source: Iowa State University Extension and Outreach, Yard and Garden

Tradition

Bad

avoidgood

2 chart entries: 0 recommend, 2 advise against.

0 cited, 2 uncited.

Research

No papers found on this pair.

Yield trial

Good

1.00

1.13

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

1 field trial. Published LERs lean high.

Myth busted

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.

Tomato PotatoTomato and Potato are close relatives, so the same insects and diseases can hop from one to the other.

Same familyextension guidance x1

Crop Rotation in the Vegetable Garden (Steil · 2025 · Iowa State University Extension and Outreach, Yard and Garden)

Tomato PotatoMedian land equivalent ratio 2.12 over 1 trial: growing them together gave 2.12 times the harvest of two separate plots of the same size.

Partial LERs (medians): Tomato 1.00 + Potato 1.13. Range across treatments 1.47 to 2.76. 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

Phosphite alters the behavioral response of potato tuber moth (Phthorimaea operculella) to field-grown potato (Mulugeta · 2019)

Tradition saysBad

2 gardening-lore entries, 2 without a specific citation. Lore is a starting point, not proof.

None of the 2 tradition entries cite a specific source.

Companion plants for both tomatoes and potatoes

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

Plant	With tomatoes	With potatoes
Broccoli	No trial foundNot tested. Charts: recommend.Evidence for tomatoes and broccoli	Bigger combined harvestField trial, 2 studies. Charts: not listed.Evidence for potatoes and broccoli

Recommended by garden charts for both, not tested yet

Garlic Thyme

The evidence, with sources

Yield trialGood1 entry

GoodLER 2.12field trial

Ethiopia, 2015-2016; NA design; median LER 2.12 over 8 treatment(s) · partial LER Potato 1.125, Tomato 1
Phosphite alters the behavioral response of potato tuber moth (Phthorimaea operculella) to field-grown potato (Mulugeta · 2019)

TraditionBad2 entries

Badadvises against
Potato: avoid tomato
List of companion plants (uncited entry) (Wikipedia)
Badadvises against
Tomatoes: avoid potatoes
List of companion plants (uncited entry) (Wikipedia)

Same familyShares pests1 entry

Both in Solanaceae: often susceptible to the same diseases and insects
Crop Rotation in the Vegetable Garden (Steil · 2025 · Iowa State University Extension and Outreach, Yard and Garden)

Plan a bed with tomatoes and potatoes

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

Have you grown tomatoes and potatoes 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.