When to Plant Lettuce in Hawaii
Published: April 21, 2026
Hawaii gardeners in Zone 12a have essentially year-round growing for lettuce. Cool-season crops like lettuce are best planted in the cooler winter months (October through February) — summer heat prevents these plants from heading or forming a harvestable crop. This guide gives exact dates for Hawaii based on your local frost calendar.
Lettuce Planting Dates for Hawaii
| Start seeds indoors | Year-round (avoid peak summer heat) |
| Last frost (average) | Frost-free |
| Transplant outdoors | Year-round (October–March is primary window) |
| Direct sow outdoors | Year-round (October–March is primary window) |
| Expect first harvest | 45–120 days after planting |
| Fall crop start | October |
| Fall harvest | January–March |
| First fall frost (average) | Frost-free |
Growing Lettuce in Hawaii's Climate
Hawaii's tropical climate gives lettuce year-round potential, but not all months are equal. Wet season (May through October in most of Hawaii) brings disease pressure that can destroy a lettuce crop within days if fungal conditions align. Dry season (November through April) is the primary productive window.
Soil drainage matters more in tropical climates than almost anywhere else. Raised beds or heavily amended beds with 50% compost content drain rainfall quickly and keep lettuce roots oxygenated during heavy storms. Flat beds in native clay soil often fail the first wet season.
Common lettuce pests to watch for in Hawaii include Aphids and Slugs. The first line of defense is companion planting: Carrot and Radish planted nearby discourage several of these pests by confusing host-plant identification or repelling adults before they can lay eggs. Weekly garden walks in the early morning catch problems when they're still manageable.
Lettuce Garden Calendar for Hawaii
| Month | Task | Notes |
|---|---|---|
| January | First harvests | Early transplants reach harvest size |
| February | Main harvest month | Peak production month in tropical climate |
| March | Continue harvests | Last window for new plantings before wet season |
| April | Finish harvests | Wet season approaching — harvest ripe crops |
| May | Clear beds | Disease pressure rises with wet season; warm-season ornamentals now |
| June ← | — | |
| July | — | |
| August | — | |
| September | — | |
| October | Prime planting window opens | Direct sow or transplant lettuce; dry season begins |
| November | Main planting month | Peak planting window for best harvests |
| December | Continue successions | Plant every 2–3 weeks for staggered harvest |
Lettuce Growing Tips for Hawaii Gardeners
- •Direct sow very shallowly — lettuce seeds need light to germinate; cover with just 1/8 inch of soil.
- •Cut outer leaves 1 inch above the crown for "cut-and-come-again" harvests lasting weeks.
- •Hawaii's tropical climate favors planting lettuce in dry season (October through April). Wet season plantings are destroyed by fungal disease within weeks.
- •Provide afternoon shade in warmer climates (Zones 7+) to extend the spring window before heat bolts plants.
Companion Planting for Lettuce in Hawaii
In Hawaii's tropical climate, planting lettuce with Carrot and Radish helps deter pests and improve soil. Avoid planting near Fennel and Celery, which inhibit lettuce growth through root chemistry or shared pest pressure. See the full lettuce companion planting guide for the complete list.
Lettuce Planting Dates by City in Hawaii
Top cities in Hawaii — select for city-level frost dates and planting calendars.
Frequently Asked Questions
When should I plant lettuce in Hawaii?
In Hawaii (Zone 12a), start lettuce seeds indoors around Year-round (avoid peak summer heat) and transplant outdoors around Year-round (October–March is primary window) — 4 weeks before the state's average last frost of Frost-free.
What is the last frost date in Hawaii?
Hawaii's average last frost date is Frost-free in the state's most common Zone 12a. Frost dates vary by city — higher elevations and northern counties run 1 to 3 weeks later than the state average. See the city list below for city-level frost dates.
Can I grow lettuce year-round in Hawaii?
Yes, Hawaii's frost-free climate supports year-round lettuce growing. October through March is the primary productive window; summer heat and wet-season fungal pressure limit what you can grow June through September.
What lettuce varieties grow best in Hawaii?
For Hawaii's Zone 12a, Bolt-resistant Jericho, Slobolt, and Summer Bibb extend the usable spring window.
When do I start lettuce seeds indoors in Hawaii?
Start lettuce seeds indoors in Hawaii around Year-round (avoid peak summer heat), which is 4 weeks before the state's average last frost of Frost-free. Use grow lights and keep soil temperatures at 70–75°F for fastest germination.