Can you plant lettuce and squash together?

Yes. Lettuce and squash grow well together. A shared bed gave about 10% 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 lettuce and squash work together

More harvest from the same bed. In one field trial, a bed with both crops gave about 10% more harvest than the same space split into a lettuce bed and a squash & pumpkin bed.
Effect of intercropping on the performance of some summer vegetable crops grown under different row arrangements (Hadidi · 2011)

What to plant with lettuce and squash

Good neighbours of both, best tested first.

BeanWith lettuce: 48% more harvestWith squash: 17% more harvest
OkraWith lettuce: 9% more harvestWith squash: About the same harvest

How each one was tested, with the evidence

What to keep away from lettuce and squash

CeleryWith lettuce: Garden charts advise against it, not tested
ParsleyWith lettuce: Garden charts advise against it, not tested
PotatoWith squash: 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 papers found on this pair.

Yield trial

Good

No per-crop split reported in these trials.

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.

Companion plants for both lettuce and squash

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

Plant	With lettuce	With squash
Bean	48% more harvest from the same spaceField trial, 2 studies. Charts: recommend.Evidence for lettuce and beans	Fewer pests and better soil and nutrient uptake17% more harvest from the same spaceField trial, 7 studies. Charts: recommend.Evidence for squash and beans
Okra	9% more harvest from the same spaceField trial, 1 study. Charts: recommend.Evidence for lettuce and okra	About the same harvest as separate bedsField trial, 1 study. Charts: recommend.Evidence for squash and okra

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

Yield trialGood1 entry

GoodLER 1.10field trial

Jordan, 2007; Replacement design; median LER 1.10 over 4 treatment(s)
Effect of intercropping on the performance of some summer vegetable crops grown under different row arrangements (Hadidi · 2011)

Plan a bed with lettuce and squash

All neighbours of lettuce and of squash & pumpkin, or every pair at once in the companion planting chart.

Have you grown lettuce and squash 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.