USDA zone 11a in California
USDA plant hardiness zone 11a in California is effectively frost-free: NOAA's 1991–2020 normals record no meaningful 32°F freeze at any of the 4 locations in this group (Los Angeles, CA, Los Angeles, CA, San Diego, CA, San Diego, CA), so the growing season runs all 365 days. Every location keeps its own nearest-station match and its own hardiness zone, both listed in the table below. The printable planting calendar uses Los Angeles's data as this group's representative reading.
- USDA zone
- 11a40 to 45 °F
- Last frost range
- Nonefrost-free
- First frost range
- Nonefrost-free
- Growing season range
- 365days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Los Angeles * | — | Los Angeles Intl Ap | frost-free | frost-free | 365 |
| Los Angeles | — | U C L A | frost-free | frost-free | 365 |
| San Diego | — | North Island Nas | frost-free | frost-free | 365 |
| San Diego | — | San Diego Lindbergh Fld | frost-free | frost-free | 365 |
* Los Angeles is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Los Angeles, representative)
Computed from Los Angeles's average frost dates — the median-season location in this Californiazone 11a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Pepper | Very tender | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Cucumber | Tender | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Summer squash / zucchini | Tender | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Bush bean | Tender | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Sweet corn | Tender | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Basil | Very tender | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Lettuce | Half-hardy | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Pea | Hardy | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Spinach | Hardy | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Carrot | Half-hardy | — | year-round* | — | — | grows across most of the year (no frost limit) |
| Broccoli | Half-hardy | — | year-round* | — | — | grows across most of the year (no frost limit) |
*Frost-free: planting timing is governed by summer heat rather than frost — each crop's notes flag the hot-season limit. See the methodology for how the heat regime is handled.
Which crops fit this growing season
Los Angeles's growing season runs all 365 days, so every one of the 12 crops on this page grows across most of the year here — peak summer heat, not frost, is what limits timing (see the notes above).
Frost & freeze dates (Los Angeles)
Los Angeles is effectively frost-free — NOAA's 1991–2020 normals record essentially no 32°F freeze at the nearest station, so the growing season is treated as year-round (365 days).
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | — | — | — | — | 365 |
| 32°F (freeze) | — | — | — | — | 365 |
| 28°F | — | — | — | — | 365 |
| 24°F | — | — | — | — | 365 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 4 locations is 5,168; Los Angeles's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 4,986 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 8,632 | cool-season crops (brassicas, greens) |
Hardiness zone 11a in California
Zone 11a means an average annual extreme minimum winter temperature of about 40 to 45 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. California spans 12 hardiness zones in this dataset — see all California locations for the full range, including zones5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b.
Explore zone 11a in other states at zone 11a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 11a mean in California?
- Zone 11a means an average annual extreme minimum winter temperature of 40 to 45 °F — the standard USDA measure of which perennials survive winter. 4 locations in California fall in this zone. It does not set planting dates; see the frost calendar below for that.
- When should I plant tomatoes in California's zone 11a?
- Los Angeles (this page's representative location) records no meaningful 32°F freeze in NOAA's 1991–2020 normals, so there is no last-frost date to count from — frost-free: plantable much of the year. No frost limit at this location; warm-season crop can be grown across most of the year. Peak summer heat can still reduce fruit set (roughly Jun-Aug in the hottest low-desert/tropical sites).
- Does every location in California's zone 11a have the same frost dates?
- All 4 locations on this page are effectively frost-free, so yes — timing is governed by summer heat rather than frost.
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.