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 bedClimate fitUrban core · USDA 9b–10a · Valley suburbs · USDA 9a–9b · Desert outskirts · USDA 8b–9bCrop familyAsteraceae (daisy)Life cycleAnnual cropPhoenix 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 headsFrostTolerates light frost once established; cover during a hard freeze.Time to harvestAbout 30–90 days, depending on leaf or head harvestSuccessionSow every 2–3 weeks for steady salad leaves.Special categoriesEDIBLETypical harvestFall through spring; pick leaves young or harvest heads before bolting.
Before you plant
These conditions determine whether it will thrive.
Cold hardinessCover in a hard freeze below 28°F
Once seedlings are about an inch tall they shrug off light frost, but leaves can burn in the upper 20s. Cover young plants on the coldest December to February nights.
Leaves and wood: damaged below 28°FHeat toleranceNeeds afternoon shade
Heat and longer days make it bolt and turn bitter, so it fades once days stay in the 80s, usually late March or April in Phoenix. Get the last seeds in by February.
