USDA hardiness zone lookup
Costa Mesa, CA — USDA Zone 10b
Costa Mesa, California · 360-day growing season
Frost dates and growing season in Costa Mesa
| USDA hardiness zone | Zone 10b |
|---|---|
| Average last spring frost | frost rare |
| Average first fall frost | frost rare |
| Growing season length | ~360 days |
| Temperature range (F) | 30 to 40°F |
| Temperature range (C) | -1 to 4°C |
All of Costa Mesa's mapped ZIP codes fall in the same hardiness band, Zone 10b.
These are 50%-probability averages modeled from Costa Mesa's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by frost rare, but a colder-than-average year can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.
Growing season in Costa Mesa
Costa Mesa, California sits in USDA Zone 10b, with roughly 360 frost-free days between an average last spring frost around frost rare and a first fall frost around frost rare. That is a near year-round season — the limiting factor is summer heat, not frost, so schedule cool-season crops for winter and protect tender ones from extreme highs.
What grows in Costa Mesa
Costa Mesa falls in USDA Zone 10b, so the same hardiness constraints apply as the full Zone 10 guide. Vegetables, herbs, and fruit trees rated to Zone 10b (or hardier) will overwinter here in a typical year.
- Tomatoes (winter crop, summer break)
- Citrus (full range)
- Avocado
- Mango, papaya, passion fruit
- Banana
- Pineapple
- Tropical herbs (lemongrass, Thai basil)
- Sweet potatoes
- Eggplant (year-round)
- Hot peppers
What to plant in Costa Mesa this week
Warm-season tropicals do well in Costa Mesa right now. Watch for midsummer heat stress on tomatoes — short-day varieties or shade cloth help.
- When to plant tomatoes in zone 10
- When to plant peppers in zone 10
- When to plant basil in zone 10
- When to plant cucumbers in zone 10
- When to plant summer squash in zone 10
Full planting calendar for Costa Mesa
Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 10 averages:
- When to plant tomatoes in zone 10
- When to plant peppers in zone 10
- When to plant basil in zone 10
- When to plant garlic in zone 10
- When to plant lettuce in zone 10
- When to plant bush beans in zone 10
- When to plant cucumbers in zone 10
- When to plant summer squash in zone 10
- When to plant peas in zone 10
- When to plant carrots in zone 10
ZIP codes in Costa Mesa
Drill down to the precise frost window and planting calendar for a specific ZIP in Costa Mesa:
Local microclimate notes
Zone tables give you the average — but Costa Mesagardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record — the last time you actually got frost damage — beats any national average.
Source and methodology
Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from Costa Mesa's USDA hardiness zone and regional NOAA 1991-2020 climate normals — zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations draw on US Cooperative Extension references, curated by the Growli editorial team. Last reviewed June 2026.
Other cities in California
- Adelanto, CA — USDA Zone 8b
- Anaheim, CA — USDA Zone 10b
- Bakersfield, CA — USDA Zone 9b
- Bell Gardens, CA — USDA Zone 10b
- Berkeley, CA — USDA Zone 10a
- Beverly Hills, CA — USDA Zone 10b
- Carlsbad, CA — USDA Zone 10b
- Chino, CA — USDA Zone 10a
- Chula Vista, CA — USDA Zone 10b
- Clovis, CA — USDA Zone 9b
- Crescent City, CA — USDA Zone 9a
- El Cajon, CA — USDA Zone 10a
- All of California by zone