USDA Zone 10 planting calendar
When to plant brussels sprouts in USDA zone 10
Sowing, transplant, and harvest dates calibrated to zone 10's 365-day season (South Florida, Coastal Southern California, Hawaii (parts)).
Key dates for brussels sprouts in zone 10
| Stage | When | Anchor |
|---|---|---|
| Direct sow outdoors | October — February (the cool dry season is your spring) | No frost — plant in the cool months |
| First harvest (estimate) | ~90 days after sowing | ~90 days from sow |
Dates are zone-wide averages. Local microclimates (south-facing slopes, urban heat, lakeside warmth, elevation) can shift the planting window by 1-2 weeks within the same zone.
Why this timing works for zone 10
Zone 10 has average annual minimum temperatures of 30 to 40°F and a 365-day frost-free window from frost rare or never to frost rare or never. Brussels Sprouts are hardy enough to handle light frost — and in fact prefer cool weather. They bolt or turn bitter once daytime temperatures consistently climb above 24 °C, which is why earlier is better in zone 10.
Brussels sprouts are a long-season crop — transplant outdoors 2–3 weeks before the last spring frost once seedlings are 10–15 cm tall, or start a fall crop by counting back 90–100 days from the first fall frost and setting transplants then. Flavour sweetens after the first hard frost (below -2 °C), making them one of the few vegetables that actually improves with autumn cold. Zones 9–10 can grow them as a winter crop but the lack of hard frost reduces flavour development.
Quick-grow guide
- Sun: Full sun — 6+ hours direct.
- Soil temperature for germination: 7-29 °C (45-85 °F).
- Spacing: 18-24 inches (45-60 cm) between plants.
- Days to harvest from direct sow: ~90 days.
- Plant in cool weather and provide afternoon shade once temperatures climb above 24 °C.
Common mistakes — zone 10 × brussels sprouts
- Spring planting: zone 10 springs are too short — sow brussels sprouts in autumn for a winter and early-spring harvest instead.
- Waiting for "warm" soil — these crops germinate at 7-10 °C and bolt the moment summer heat sets in.
Source and methodology
Frost-date averages from NOAA Climate Data Online within each USDA hardiness zone. Hardiness zone boundaries from the USDA Plant Hardiness Zone Map (2023). Crop timing offsets calibrated against US Cooperative Extension Service publications (UNL, UMN, NC State, Texas A&M, UF/IFAS) and cross-checked against the RHS sowing calendar for en-GB readers. Curated by the Growli editorial team.
Keep going
- How to grow brussels sprouts — full guide
- USDA Zone 10 — frost dates and what else to plant
- All 13 USDA hardiness zones