Carrots can be grown in Zone 12, but they are a cool-season root and they will test your patience: germination takes 14–21 days, the roots grow slowly in warm soil, and a sowing made outside the coolest months gives short, tough roots that bolt before they size up. Sown in the coolest months, in deep, loose soil, they reward you with sweet roots in 60–80 days.
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 | 14–21 days |
| Days to maturity | 60–80 days |
| Sowing | direct sow |
| Sun | full sun |
| Soil pH | 6.0–6.8 |
| Spacing | 2–3 inches |
| Water needs | moderate |
| Cold tolerance | hardy |
When to plant carrots in Zone 12
Plant carrots in Zone 12 in the coolest months only, roughly December through February. Seeds germinate in 14–21 days and the crop matures in 60–80 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 carrots in Zone 12
Sow carrots direct where they are to grow — they do not transplant, because any check to the root makes forked carrots. Germination takes 14–21 days, which is slow, so keep the seed bed constantly damp with a light mulch or a board laid over the row until seedlings appear. Sow thinly and thin seedlings to 2–3 inches apart once they are big enough to handle.
See also when to plant carrots in Zone 11 for the same crop in a slightly cooler zone.
Soil, spacing, sun and water
Carrots need deep, loose, stone-free soil with a pH of 6.0–6.8 — this is the single most important factor. Forked, stunted roots almost always mean compacted or stony soil, so dig the bed deeply and work in well-rotted compost, but avoid fresh manure, which causes forking. They need full sun, though light afternoon shade helps in Zone 12. They need full sun and a soil pH of 6.0–6.8. Water needs are moderate: water deeply and regularly at the base, in the morning, so leaves dry before night. The germination time calculator can help you plan the bed before you plant.
Companion planting
Onions, lettuce, rosemary, tomatoes and sage are good companions for carrots. Onions are the classic partner, lettuce uses the space between young carrot rows, and rosemary and sage are aromatic herbs that share the bed without competing for the same root space. The companion planting finder can suggest combinations for your whole bed, and our guide to when to plant beets in Zone 12 shows another crop that shares the same planting windows.
Pests and problems
The common pests and problems to watch for with carrots are carrot rust fly, aphids, wireworms. Carrot rust fly maggots tunnel into roots; cover the bed with fine mesh and avoid sowing carrots in the same bed year after year. Aphids cluster on soft new growth and leaf undersides; wash them off with a strong jet of water and encourage ladybirds. Wireworms are soil grubs that bore into roots and tubers; rotate crops and dig the bed over before sowing. Your local extension service can confirm an identification if the damage is severe.
Harvest and storage
Harvest carrots when the shoulders at the top of the root are full and the colour looks right for the variety — in Zone 12, pull them while they are still young and sweet rather than waiting for maximum size. Loosen the soil with a fork first so roots come out whole. Fresh carrots keep for several weeks in the fridge in a bag. Cut the tops off before storing, because the leaves keep drawing moisture out of the root.
Frequently asked questions
When should I plant carrots in Zone 12?
Plant carrots 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 are my carrots forked and stunted?
Forked roots are almost always a soil problem: stones, compacted ground or fresh manure make the root split and branch. In Zone 12, deep, loose, well-worked soil matters more than feeding — dig the bed over, remove stones, and use only well-rotted compost.
Can I grow carrots 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.
Why did my carrot seed take so long to come up?
Carrots are slow: germination takes 14–21 days, and the seed bed must stay damp the whole time or the seed dies. In Zone 12 the surface dries fast, so cover the row lightly with mulch or a board until seedlings appear, and be patient.