Arizona · zones 5b–10a
When to plant lettuce in Arizona.
Sow between Dec 29 to Feb 12 in a typical year, keyed to Arizona's median last frost around Feb 5. A second, fall sowing fits Sep 1 to Oct 31. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Lettuce dates for a typical Arizona season.
Direct sow
Dec 29 to Feb 12
Keyed to the ~Feb 5 last frost. Sow 0.25" deep, 6" apart.
Fall round
Sep 1 to Oct 31
Counted back from the ~Nov 15 first frost.
Harvest
~45 days later
~0.4 lb per plant over ~1 weeks.
Arizona spans more than one climate: Zone 9 is the most common zone, but the state runs 5b to 10a. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
In Arizona: watch for
The pests that find lettuce here.
With about 283 frost-free days, lettuce, leaf spends longer in the ground here than in most of the country, which widens the window in which aphids can find it. Scout weekly from midseason and act on the first signs.
Clusters tucked into the heart of the head.
Organic fix: Rinse well; insecticidal soap on young plants.
Ragged holes and slime trails, worse after rain.
Organic fix: Iron-phosphate bait; a diatomaceous-earth ring; hand-pick at night.
Seedlings clipped off at the soil line overnight.
Organic fix: Collars around the stems; Bt or diatomaceous earth.
Pale yellow patches boxed in by the leaf veins, with white fuzz underneath.
Organic fix: Give plants room, let them dry between waterings, clear old leaves, and pick resistant varieties.
Your season math: Arizona gives lettuce about 283 frost-free days, and it needs roughly 45 days to a first harvest. That fits about 24 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting lettuce in Arizona: questions
When should I plant lettuce in Arizona?+
In a typical Arizona year, sow lettuce between Dec 29 to Feb 12, keyed to the state's median last frost around Feb 5. There's also a fall window: Sep 1 to Oct 31. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Arizona?+
Arizona spans zones 5b–10a, mostly zone 9. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many lettuce plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.