USDA Zone 9 planting calendar
When to plant lettuce in USDA zone 9
Sowing, transplant, and harvest dates calibrated to zone 9's 280-day season (Central + South Florida, Southern Texas, Southern California, Arizona).
Key dates for lettuce in zone 9
| Stage | When | Anchor |
|---|---|---|
| Indoor seed start | late January (January 27) | 4 weeks before last frost |
| Outdoor transplant | early February (February 3) | 21 days before last frost (mid-February to early March) |
| First harvest (estimate) | late March (March 25) | ~50 days from transplant |
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 9
Zone 9 has average annual minimum temperatures of 20 to 30°F and a 280-day frost-free window from mid-February to early March to late November / early December. Lettuce 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 9.
Lettuce is genuinely cold-hardy — direct-sow as soon as soil can be worked, 2-4 weeks before the last spring frost. It bolts and turns bitter in summer heat above 24 °C, so southern zones grow it as a winter and shoulder-season crop instead of in midsummer.
Quick-grow guide
- Sun: Full sun in cool weather, light shade in heat.
- Soil temperature for germination: 10-21 °C (50-70 °F).
- Spacing: 6-12 inches (15-30 cm) between plants.
- Days to harvest from transplant: ~50 days.
- Plant in cool weather and provide afternoon shade once temperatures climb above 24 °C.
Common mistakes — zone 9 × lettuce
- Spring planting: zone 9 springs are too short — sow lettuce 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 lettuce — full guide
- USDA Zone 9 — frost dates and what else to plant
- All 13 USDA hardiness zones
Same crop, nearby zones
- When to plant lettuce in USDA zone 7
- When to plant lettuce in USDA zone 8
- When to plant lettuce in USDA zone 10
- When to plant lettuce in USDA zone 11