Cool-season produce

Lettuce

Lactuca sativa

Also known as Romaine · Butterhead lettuce · Iceberg lettuce · Leaf lettuce

Sow after the worst soil heat passes. Harvest outer leaves or cut whole heads; heat and lengthening days bring bitterness and bolting.

EdibleCool-season crop

Growing spaceVegetable bed

Climate fitUrban core · USDA 9b–10a · Valley suburbs · USDA 9a–9b · Desert outskirts · USDA 8b–9b

Crop familyAsteraceae (daisy)

Life cycleAnnual crop

Phoenix planting windowSeptember–January; late winter sowings need quick-maturing varieties.

How to plantDirect sow or set out transplants; use head types as transplants for a head start.

Plant spacing6–12 in for leaf types; 10–12 in for heads

FrostTolerates light frost once established; cover during a hard freeze.

Time to harvestAbout 30–90 days, depending on leaf or head harvest

SuccessionSow every 2–3 weeks for steady salad leaves.

Special categoriesEDIBLE

Typical harvestFall through spring; pick leaves young or harvest heads before bolting.

Right plant, right place

Will Lettuce grow at your Arizona property?

Sow after the worst soil heat passes. Harvest outer leaves or cut whole heads; heat and lengthening days bring bitterness and bolting.

Best regional fit: Urban core · USDA 9b–10a, Valley suburbs · USDA 9a–9b, Desert outskirts · USDA 8b–9b.

Light

Full winter sun; give leafy crops afternoon protection during warm fall and spring weather.

Water

Keep the vegetable root zone evenly moist with regular irrigation; adjust to rain, soil, and temperature rather than using a fixed summer schedule.

Planting & stewardship

1
Prepare a fertile, well-drained bed and keep seed or transplants evenly moist through establishment.
2
Thin to the final spacing; crowding reduces harvest quality.
3
Watch for aphids and caterpillars and protect sensitive growth from a hard freeze.
4
Harvest before sustained spring heat causes bolting or poor quality.

Read the growing reference ↗ Planting dates can shift with cultivar, weather, and your yard’s microclimate.