When to Plant Turnips in Hawaii
Published: April 24, 2026
Hawaii gardeners in Zone 12a have essentially year-round growing for turnip. Cool-season crops like turnip 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.
Turnip Planting Dates for Hawaii
| 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 |
⚠ Direct sow turnips 2–4 weeks before last frost for spring crop. Best planted in late summer (6–8 weeks before first fall frost) for fall harvest — frost sweetens the roots. Fast-growing: some varieties ready in just 35 days.
Growing Turnips in Hawaii's Climate
Hawaii's tropical climate gives turnip 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 turnip 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 turnip roots oxygenated during heavy storms. Flat beds in native clay soil often fail the first wet season.
Common turnip pests to watch for in Hawaii include Flea Beetle and Aphid. The first line of defense is companion planting: Pea and Mint 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.
Turnip 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 turnip; dry season begins |
| November | Main planting month | Peak planting window for best harvests |
| December | Continue successions | Plant every 2–3 weeks for staggered harvest |
Turnip Growing Tips for Hawaii Gardeners
- •Thin seedlings to 4-inch spacing when plants are 3 inches tall — crowded turnips produce small woody roots.
- •Both roots AND greens are edible — harvest baby turnip greens 4 weeks after sowing, roots 5–9 weeks.
- •Hawaii's tropical climate favors planting turnip in dry season (October through April). Wet season plantings are destroyed by fungal disease within weeks.
- •Fall turnips are sweetest — plant 8 weeks before first frost and let cold weather convert starches to sugars.
Companion Planting for Turnips in Hawaii
In Hawaii's tropical climate, planting turnip with Pea and Mint helps deter pests and improve soil. Avoid planting near Potato and Radish, which inhibit turnip growth through root chemistry or shared pest pressure. See the full turnip companion planting guide for the complete list.
Turnips 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 turnip in Hawaii?
In Hawaii (Zone 12a), direct sow turnip around Year-round (October–March is primary window) — 3 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 turnip year-round in Hawaii?
Yes, Hawaii's frost-free climate supports year-round turnip 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 turnip varieties grow best in Hawaii?
For Hawaii's Zone 12a, consult a local nursery or extension office for turnips variety recommendations.
When do I start turnip seeds indoors in Hawaii?
Turnip does not need indoor starting in Hawaii — direct sow around Year-round (October–March is primary window) once soil reaches 40°F. Indoor starting is not recommended for this crop because turnip transplants poorly.