Thousand Oaks, CA 90290 planting calendar
- USDA zone
- 10b35 to 40 °F
- Last frost
- Jan 24avg, 32°F
- First frost
- Dec 15avg, 32°F
- Growing season
- 329days
Thousand Oaks, California is in USDA plant hardiness zone 10b. Its average last spring frost is around January 24 and the first fall frost around December 15, giving a growing season of about 329 days (NOAA 1991–2020 normals, 32°F, median). Start tender crops like tomatoes and peppers indoors weeks before the last frost and set them out afterward; sow hardy crops such as peas, spinach, and lettuce before it. The planner below turns those frost dates into a printable per-crop planting calendar.
Thousand Oaks planting calendar
Each crop's windows are counted from Thousand Oaks's average frost dates. 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.
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting |
|---|---|---|---|---|---|
| Tomato | Tender | Jan 1 | Jan 31 – Feb 7 | Apr 1 – Apr 21 | — |
| Pepper | Very tender | Jan 1 | Feb 7 – Feb 14 | Apr 8 – May 8 | — |
| Cucumber | Tender | Jan 1 – Jan 3 | Jan 31 – Feb 7 | Mar 22 – Apr 11 | — |
| Summer squash / zucchini | Tender | — | Jan 31 – Feb 7 | Mar 17 – Apr 1 | — |
| Bush bean | Tender | — | Jan 31 – Feb 7 | Mar 22 – Apr 1 | Oct 16 – Oct 26 |
| Sweet corn | Tender | — | Jan 24 – Feb 7 | Mar 25 – Apr 24 | — |
| Basil | Very tender | Jan 1 | Jan 31 – Feb 7 | Mar 2 – Mar 17 | — |
| Lettuce | Half-hardy | Jan 1 | Jan 1 – Jan 10 | Feb 15 – Mar 2 | Oct 2 – Oct 17 |
| Pea | Hardy | — | Jan 1 | Feb 25 – Mar 12 | Sep 22 – Oct 7 |
| Spinach | Hardy | — | Jan 1 | Feb 10 – Feb 20 | Oct 12 – Oct 22 |
| Carrot | Half-hardy | — | Jan 3 – Jan 10 | Mar 4 – Mar 24 | Sep 12 – Oct 2 |
| Broccoli | Half-hardy | Jan 1 | Jan 1 – Jan 10 | Feb 25 – Mar 17 | Sep 17 – Oct 7 |
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.
Frost & freeze dates
From NOAA's 1991–2020 Climate Normals at station USC00049785. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 (p10 for spring, p90 for fall) — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Mar 2 | Apr 7 | Nov 29 | Dec 19 | 271 |
| 32°F (freeze) | Jan 24 | Mar 5 | Dec 15 | Jan 26 | 329 |
| 28°F | Dec 31 | Feb 1 | Dec 26 | Jan 25 | 365 |
| 24°F | — | — | — | — | 365 |
32°F is the standard "freeze" line that damages tender crops; lighter 36°F frost can nip the most cold-sensitive plants, while hardy crops shrug off light frost down toward 28°F. Use the threshold that matches what you are protecting.
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. Warm-season crops need a long, warm GDD total; a short, cool GDD total favors greens and brassicas.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 6,002 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 9,608 | cool-season crops (brassicas, greens) |
Hardiness zone 10b
Thousand Oaks sits in USDA plant hardiness zone 10b on the 2023 map — meaning its average annual extreme minimum winter temperature is about 35 to 40 °F. That number 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.
Explore more places in zone 10b, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Thousand Oaks?
- Thousand Oaks, California is in USDA plant hardiness zone 10b on the 2023 map (average annual extreme minimum temperature 35 to 40 °F) — from the USDA Plant Hardiness Zone Map 2023, matched to this location's ZIP. See the methodology page for sources.
- When is the last frost in Thousand Oaks?
- The average (median) last spring frost at 32°F is around January 24, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as March 5, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Thousand Oaks?
- The average first fall frost at 32°F is around December 15. That leaves a growing season of about 329 days between the average last spring and first fall frosts.
- When should I start tomatoes in Thousand Oaks?
- Start tomato seeds indoors about Jan 1 and transplant them outside about Jan 31 – Feb 7, once the danger of frost has passed. Estimated first harvest is around Apr 1 – Apr 21.
- How long is the growing season in Thousand Oaks?
- About 329 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~January 24) and the average first fall frost (~December 15). Cold-hardy crops extend usable time at both ends; frost-tender crops fit inside it.
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020 for station USC00049785 (Woodland Hills Pierce College, 9.1 km away). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to this 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.