USDA Zone 12 planting calendar
When to plant basil in USDA zone 12
Sowing, transplant, and harvest dates calibrated to zone 12's 365-day season (Hawaii (lowland), Puerto Rico (parts)).
Key dates for basil in zone 12
| Stage | When | Anchor |
|---|---|---|
| Plant outdoors | year-round (avoid the hottest 6-8 weeks of summer for heat-sensitive varieties) | No frost — plant in the cool months |
| First harvest (estimate) | ~60 days after planting | ~60 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 12
Zone 12 has average annual minimum temperatures of 50 to 60°F and a 365-day frost-free window from no frost to no frost. Basil are tender — they need soil above 16 °C to grow and stop fruiting once nights drop below 10 °C. That puts the safe outdoor planting window after the last spring frost passes, and the harvest closes when fall temperatures arrive.
Basil is one of the most cold-sensitive common herbs — it sulks below 10 °C and dies in light frost. Wait a full week after the last spring frost before moving transplants outside, or direct-sow two weeks after frost when soil hits 18 °C.
Quick-grow guide
- Sun: Full sun — 6+ hours direct.
- Soil temperature for germination: 20-25 °C (68-77 °F).
- Spacing: 8-12 inches (20-30 cm) between plants.
- Days to harvest from direct sow: ~60 days.
- Wait until night temperatures stay above 10 °C — cold soil stunts warm-season crops permanently.
Common mistakes — zone 12 × basil
- Planting in midsummer: zone 12's July-August heat shuts down fruit set — run a spring crop (transplant by year-round (avoid the hottest 6-8 weeks of summer for heat-sensitive varieties)) and a fall crop instead.
- Choosing cold-zone varieties — pick heat-tolerant cultivars (Solar Fire, Heatwave II for tomatoes; Carolina Reaper-tolerant heritage peppers) bred for zone 12.
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 basil — full guide
- USDA Zone 12 — frost dates and what else to plant
- All 13 USDA hardiness zones
Same crop, nearby zones
- When to plant basil in USDA zone 10
- When to plant basil in USDA zone 11
- When to plant basil in USDA zone 13