Hawaii · zones 12a–12a
When to plant lettuce in Hawaii.
Sow between Nov 24 to Jan 8 in a typical year, keyed to Hawaii's median last frost around Jan 1. A second, fall sowing fits Oct 17 to Dec 16. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Lettuce dates for a typical Hawaii season.
Direct sow
Nov 24 to Jan 8
Keyed to the ~Jan 1 last frost. Sow 0.25" deep, 6" apart.
Fall round
Oct 17 to Dec 16
Counted back from the ~Dec 31 first frost.
Harvest
~45 days later
~0.4 lb per plant over ~1 weeks.
Hawaii spans more than one climate: Zone 12 is the most common zone, but the state runs 12a to 12a. 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.
Hawaii growing notes
Leaf lettuce, not a head type, is what gets planted here, and that choice does real work against a climate with no true winter.
A leaf type is scheduled here, not a head, and that is not an accident
The crop scheduled on this calendar is leaf lettuce, not a head type, and that is not a small detail. A head, butterhead or crisphead, needs weeks of steady mild weather to fold its inner leaves into a tight ball, and holds that shape only briefly before it splits or turns bitter. Leaf lettuce skips that step; it grows as an open rosette, cut a little at a time, so there is no single stage where warm weather can ruin the whole plant at once. Seed goes a quarter inch deep, thinned to about 6 inches apart, with a first cutting around 45 days out and a modest return, under half a pound of leaf, from a single plant.
That does not mean this crop shrugs off the missing cool season, only that it fails more gracefully than a head type would. Watch the center of the plant, not the outer leaves, for the real warning: once the crown pushes a stem up out of the rosette and new leaves come in narrower and more pointed than the ones before them, the plant has begun bolting, and flavor turns bitter fast from there. Taste a leaf at the first sign of that stretch, rather than waiting for the whole plant to change, to catch it before it spreads through the row.
Thirty-two sowings a year answers a question before it gets asked
No other crop on this list gets scheduled for as many separate sowings as lettuce, up to 32 across the year. That number is really an admission about how this crop behaves here: a stand holds decent quality for a short stretch and then turns, so the way to keep supply steady is a fresh short row going in roughly every week and a half, not one bed a household leans on for months. Treat each sowing as disposable once it turns bitter, and let the next one already coming up take over.
Harvesting by the outer leaf rather than pulling the whole plant stretches a sowing's useful window, since the crown keeps producing new leaves from the center as long as it has not started bolting. A little afternoon shade over the bed, even dappled shade from a taller crop to the west, eases the hottest stretch of the day and can buy a planting a few extra days of usable leaf before it turns.
Slugs, cutworms, and a mildew with no dry season to slow it
Slugs and snails do real damage on a crop this soft and low to the ground, especially anywhere the soil stays damp. The tell is ragged holes eaten from the leaf edge inward, paired with a dried, silvery slime trail on the plant or the soil nearby; checking the undersides of the lowest leaves in early morning, before the trails dry off in the sun, confirms it faster than trying to spot the pest itself during the day. A ring of coarse material like crushed eggshell around each seedling, or simply keeping leaves up off wet soil with mulch, cuts down how easily they reach the plant.
Cutworms work overnight and leave a different signature: a seedling simply gone by morning, toppled with a clean cut at the soil line rather than chewed down from the top, points to a cutworm curled in the soil nearby rather than any leaf-feeding pest. A collar pushed an inch into the soil around each transplant blocks it. Aphids cluster on the tender young leaves near the crown, worth a check whenever cutting outer leaves. Downy mildew announces itself as a patchy yellowing squared off between the leaf veins, backed by a gray, fuzzy growth on the underside that shows clearest on a damp morning; with no dry season here to interrupt it, thinning for airflow between plants matters more than where a real winter eventually breaks the cycle.
In Hawaii: watch for
The pests that find lettuce here.
With about 364 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: Hawaii gives lettuce about 364 frost-free days, and it needs roughly 45 days to a first harvest. That fits about 32 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting lettuce in Hawaii: questions
When should I plant lettuce in Hawaii?+
In a typical Hawaii year, sow lettuce between Nov 24 to Jan 8, keyed to the state's median last frost around Jan 1. There's also a fall window: Oct 17 to Dec 16. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Hawaii?+
Hawaii spans zones 12a–12a, mostly zone 12. 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.