August · USDA Zone 10
summerWhat to plant in August in USDA zone 10
Summer 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 indoors in August — zone 10
Start these seeds under lights or in a heated propagator so transplants are ready when the outdoor planting window opens.
- Fall tomatoes, peppers, eggplant for September transplant
Harvest in August — zone 10
These crops should be ready or in active harvest in August for zone 10 gardens. Pick fruiting crops every 2-3 days to keep production going.
- Tropical herbs, okra, sweet potatoes, hot peppers, citrus
Maintenance in August — zone 10
- Heaviest summer heat — minimal sowing, focus on shade and irrigation
Prep and planning — zone 10
- Plan October-March cool-season garden
Universal August tasks
These apply across most US and UK gardens in August, regardless of zone.
- Sow autumn salad, spinach, kale, and oriental greens.
- Transplant fall brassicas (broccoli, cabbage, cauliflower) in zones 4-7.
- Preserve the summer harvest — can, freeze, dehydrate, or ferment.
- Order garlic and shallots for fall planting.
- Water consistently — uneven moisture splits tomatoes and bolts greens.
- Cut and dry herbs at peak flavor (just before flowering).
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 — August
August is harvest peak and the gateway to autumn. Sow spring cabbage, winter lettuce, spinach, salad onions, and overwintering varieties of broad beans and peas. Harvest sweetcorn, tomatoes, beans, courgettes, soft fruit, and main-crop potatoes.
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
- ← July in zone 10
- September in zone 10 →
- All zones — what to plant in August
- USDA Zone 10 — frost dates and crop list
- Full 12-month planting calendar