Cabbage is a cool-season crop, and in Zone 12 that means the coolest months only: with winter lows of 50 to 60°F, cabbage heads well from a December sowing, maturing in 60–90 days, and it bolts or splits as soon as the heat returns. Grown in that window it is one of the most reliable brassicas for the tropics, giving solid, heavy heads from a small bed.
The Zone 12 challenge is heat. These are cool-season crops, and in a frost-free tropical zone the coolest months are short — plant by the coolest part of the year, give afternoon shade, and accept that the season is brief and the harvest smaller than in a cool climate.
Zone 12 at a glance
USDA Zone 12 covers the warmest lowland parts of Hawaii and Puerto Rico. Winters are very mild, with average winter lows of 50 to 60°F, frost is unknown, and the growing season runs all year. Zone 12 has no average last spring frost and no average first autumn frost — it is frost-free year-round — so planting dates here are averages and guidance, not exact dates for any one garden; check your local extension service before planting.
| Detail | Zone 12 guidance |
|---|---|
| Average winter low | 50 to 60°F |
| Average last spring frost | frost-free (no frost dates) |
| Average first autumn frost | frost-free (no frost dates) |
| Days to germination | 7–14 days |
| Days to maturity | 60–90 days |
| Sowing | both |
| Sun | full sun |
| Soil pH | 6.0–7.0 |
| Spacing | 12–24 inches |
| Water needs | moderate |
| Cold tolerance | frost-tolerant |
When to plant cabbage in Zone 12
Plant cabbage in Zone 12 in the coolest months only, roughly December through February. Seeds germinate in 7–14 days and the crop matures in 60–90 days, so a sowing made in December is ready around February to March. Zone 12 is frost-free, so there are no last or first frost dates — check your local extension service for advice on your own microclimate. Sown outside the cool window, this crop bolts, turns bitter or fails to size up in the heat, so treat the coolest months as the whole season and plan other crops for the hot months.
The planting calendar hub and the December in Zone 12 month guide show what else is happening at planting time.
Starting cabbage in Zone 12
Cabbage can be sown direct or started indoors and transplanted out as sturdy seedlings. Germination takes 7–14 days. Transplant seedlings out when they have four or five true leaves, spacing plants 12–24 inches apart depending on the variety — wider spacing gives bigger heads — and water them in well.
See also when to plant cabbage in Zone 11 for the same crop in a slightly cooler zone.
Soil, spacing, sun and water
Cabbage needs full sun and rich, moisture-holding, well-drained soil with a pH of 6.0–7.0. Dig in plenty of well-rotted compost before planting, because cabbage are heavy feeders. Space plants 12–24 inches apart, and mulch to keep roots cool and the soil evenly moist. They need full sun and a soil pH of 6.0–7.0. Water needs are moderate: water deeply and regularly at the base, in the morning, so leaves dry before night. The seed-starting calculator can help you plan the bed before you plant.
Companion planting
Marigolds, basil, onions and lettuce are good companions for cabbage. Onions and lettuce fill the ground between young plants, marigolds edge the bed, and the same companions suit broccoli and cauliflower, so the three brassicas can share a cool-season bed plan. The companion planting finder can suggest combinations for your whole bed, and our guide to when to plant broccoli in Zone 12 shows another crop that shares the same planting windows.
Pests and problems
The common pests and problems to watch for with cabbage are cabbage worms, aphids, flea beetles, slugs. Cabbage worms are green caterpillars that chew holes in leaves; check leaf undersides and hand-pick, or cover with fine mesh. Aphids cluster on soft new growth and leaf undersides; wash them off with a strong jet of water and encourage ladybirds. Flea beetles chew small holes in leaves, worst on young seedlings; fine mesh row cover and mulching help. Slugs feed at night, leaving ragged holes and slime trails; water in the morning and keep the bed clear of debris. Your local extension service can confirm an identification if the damage is severe.
Harvest and storage
Cut the head when it feels firm and solid all the way through — squeeze it gently to check. Harvest in the morning, cut with a sharp knife, and leave the stump in place: many varieties sprout small secondary heads from the stump. Fresh cabbage keeps for several weeks in the fridge, longer than most brassicas, and it stores well as sauerkraut or in cooked dishes. Keep heads cool and dry, and use any split heads first.
Frequently asked questions
When should I plant cabbage in Zone 12?
Plant cabbage in Zone 12 in the coolest months only, roughly December through February. Zone 12 is frost-free year-round, so there are no last or first frost dates — plant by the heat and the wet and dry seasons, and check your local extension service for your own microclimate.
Why did my cabbage split open?
Uneven watering is the usual cause: a dry spell followed by heavy watering or rain makes the head swell fast and split. In Zone 12, keep watering even with mulch and regular watering, and harvest heads as soon as they are firm rather than leaving them to grow bigger.
Can I grow cabbage in Zone 12 year-round?
No — not well. This is a cool-season crop, and outside the coolest months, roughly December through February, it bolts, turns bitter or fails to size up in tropical heat. Grow it in the cool window, and plant heat-loving crops in the hot months instead.
Can I grow cabbage in summer in Zone 12?
No — cabbage is a cool-season crop and summer heat makes it bolt or fail to head at all. Save cabbage for the coolest months, roughly December through February, and grow heat-loving crops such as okra, eggplant and sweet corn in the hot months instead.