December · USDA Zone 10
winterWhat to plant in December in USDA zone 10
Winter planting guide for zone 10 (South Florida, Coastal Southern California, Hawaii (parts)) — a 365-day growing season with last frost around frost rare or never and first frost around frost rare or never.
Sow outdoors in December — zone 10
Direct-sow these seeds into prepared garden beds or large containers. Soil temperature matters more than the calendar date — wait for a sustained warm-up before sowing tender crops.
- Continued cool-season sowing — main growing period
Transplant in December — zone 10
Move hardened-off seedlings into the garden. Tender crops want soil above 16 °C and night temperatures consistently above 10 °C; cool-season transplants tolerate light frost.
- Brassicas, lettuce, kale, herbs
Harvest in December — zone 10
These crops should be ready or in active harvest in December for zone 10 gardens. Pick fruiting crops every 2-3 days to keep production going.
- Full cool-season harvest — lettuce, kale, broccoli, citrus, peppers, tomatoes
Maintenance in December — zone 10
- Light frost protection in inland zone 10a only
Universal December tasks
These apply across most US and UK gardens in December, regardless of zone.
- Review this year's garden journal — what worked, what didn't, what to change.
- Start your seed list for next year while pleasure and pain are fresh.
- Check stored crops weekly for rot — winter squash, onions, garlic, potatoes.
- Force amaryllis and paperwhite bulbs for indoor color.
- Tend houseplants — many slow-grow now, so reduce watering by half.
- Prune dormant fruit trees and grapes on a dry, mild day.
Why this works for zone 10
Zone 10 has average annual minimum temperatures of 30 to 40°F (-1 to 4°C) and a frost-free window from frost rare or never to frost rare or never — about 365 growing days. Summer can be too hot for many tomato varieties. Winter is the prime growing season for cool-loving crops.
Dates are zone-wide averages. Local microclimates (south-facing slopes, urban heat, lakeside warmth, elevation) can shift the window by 1-2 weeks within the same zone.
UK gardeners — December
December is the UK's quiet month. Harvest brussels sprouts, leeks, parsnips, kale, and overwintered chard. Plant bare-root fruit trees and bushes on mild days. Force rhubarb crowns indoors. Plan next year and order seeds.
Source and methodology
Frost-date averages from NOAA Climate Data Online within USDA zone 10. Hardiness boundaries from the USDA Plant Hardiness Zone Map (2023). Crop timing curated against US Cooperative Extension Service publications (UNL, UMN, NC State, Texas A&M, UF/IFAS, Oregon State) and cross-referenced against the RHS sowing calendar. Curated by the Growli editorial team.
Keep going
- ← November in zone 10
- January in zone 10 →
- All zones — what to plant in December
- USDA Zone 10 — frost dates and crop list
- Full 12-month planting calendar