Frost Dates & Planting Calendar for Atascadero, CA
Plan your garden around Atascadero, CA's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.
Last Spring Frost
March 15
Safe Apr 13
Typical Mar 15
Risky Feb 12
First Fall Frost
November 10
Safe Oct 23
Typical Nov 10
Risky Nov 29
Growing Season
238 days
Typical last frost to typical first frost.
USDA Hardiness Zone
Zone 9a
Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.
Data: NOAA station PASO ROBLES, CA US, 15.4 km away.
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days until the typical last spring frost
Monthly Temperatures
Avg. high
Avg. temp
Avg. low
Planting Calendar
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Tomato | Jan 18 – Feb 1 | — | Mar 22 – Mar 29 | — | 60–85 days | Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed. |
| Pepper | Jan 4 – Jan 18 | — | Mar 22 – Apr 5 | — | 60–90 days | Slow to germinate; start indoors 8-10 weeks before last frost. Transplant only once nights stay above 55F, 1-3 weeks after last frost. |
| Eggplant | Jan 4 – Jan 18 | — | Mar 29 – Apr 5 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | Feb 15 – Feb 22 | Mar 22 – Mar 29 | Mar 22 – Mar 29 | — | 50–65 days | Can be started indoors 3-4 weeks before transplanting, or direct-sown 1-2 weeks after last frost once soil is warm. |
| Zucchini | Feb 22 – Mar 1 | Mar 22 – Apr 5 | Mar 22 – Mar 29 | — | 45–55 days | Fast-growing squash; direct sow 1-3 weeks after last frost, or start indoors 2-3 weeks early for a head start. |
| Winter Squash | Feb 15 – Feb 22 | Mar 22 – Apr 5 | Mar 22 – Mar 29 | — | 80–110 days | Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates. |
| Pumpkin | — | Mar 22 – Apr 5 | — | — | 90–120 days | Direct sow 1-3 weeks after last frost; back-time from your first fall frost so the 90-120 day maturity window lands before it. |
| Watermelon | Feb 15 – Feb 22 | — | Mar 29 – Apr 5 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | Feb 15 – Feb 22 | — | Mar 29 – Apr 5 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | Mar 15 – Mar 29 | — | — | 60–100 days | Direct sow at last frost to 2 weeks after, once soil reaches 60F; does not transplant well. Succession sow every 2 weeks. |
| Green Bean | — | Mar 15 – Mar 29 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Feb 1 – Feb 15 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | Feb 15 – Mar 1 | — | Sep 15 – Sep 29 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Feb 1 – Feb 15 | — | Sep 15 – Sep 29 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | Feb 15 – Mar 1 | — | Sep 1 – Sep 15 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | Feb 15 – Mar 1 | — | Sep 29 – Oct 6 | 30–40 days | Fast-growing, cold-tolerant green; direct sow 2-4 weeks before last frost, succession sow every 2-3 weeks. |
| Swiss Chard | — | Feb 22 – Mar 8 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Jan 25 – Feb 8 | — | Feb 22 – Mar 1 | Sep 8 – Sep 15 | 55–80 days | Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost). |
| Cauliflower | Jan 25 – Feb 8 | — | Mar 1 – Mar 8 | Sep 1 – Sep 8 | 55–85 days | Fussier than broccoli about temperature swings; start indoors 5-7 weeks before last frost, transplant 1-2 weeks before last frost. |
| Cabbage | Jan 25 – Feb 8 | — | Feb 15 – Mar 1 | Sep 1 – Sep 15 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Jan 25 – Feb 8 | — | Feb 22 – Mar 8 | — | 90–110 days | Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost. |
| Carrot | — | Feb 15 – Mar 1 | — | Aug 18 – Sep 1 | 60–80 days | Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked. |
| Beet | — | Feb 15 – Mar 1 | — | Sep 1 – Sep 15 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Feb 8 – Feb 22 | — | Sep 29 – Oct 13 | 22–30 days | Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked. |
| Turnip | — | Feb 15 – Mar 1 | — | Sep 1 – Sep 15 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Jan 4 – Jan 18 | — | Feb 15 – Mar 1 | — | 90–120 days | Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings. |
| Garlic | — | — | — | Oct 13 – Oct 27 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | Feb 15 – Mar 1 | — | — | 70–120 days | Plant seed potatoes 2-4 weeks before last frost, as soon as soil can be worked and is above 45F; light frost on emerging foliage is usually tolerated. |
| Sweet Potato | — | — | Mar 29 – Apr 12 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | Feb 15 – Mar 1 | — | 730–1095 days | Perennial; plant crowns 2-4 weeks before last frost as soon as soil can be worked. Takes 2-3 years to full production. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Basil | Feb 1 – Feb 8 | — | Mar 22 – Mar 29 | — | 50–70 days | Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm. |
| Cilantro | — | Feb 22 – Mar 8 | — | Sep 15 – Sep 29 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Jan 18 – Feb 1 | — | Mar 1 – Mar 8 | — | 70–90 days | Slow to germinate; start indoors 6-8 weeks before last frost, transplant 1-2 weeks before last frost (biennial, cold-tolerant). |
| Dill | — | Feb 22 – Mar 8 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Jan 18 – Feb 1 | — | Mar 15 – Mar 22 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Jan 18 – Feb 1 | — | Mar 15 – Mar 22 | — | 85–95 days | Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Sunflower | — | Mar 22 – Apr 5 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | Feb 15 – Feb 22 | Mar 22 – Apr 5 | Mar 22 – Mar 29 | — | 60–70 days | Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms. |
| Marigold | Feb 1 – Feb 15 | — | Mar 22 – Mar 29 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | Feb 15 – Feb 22 | Mar 22 – Apr 5 | Mar 22 – Mar 29 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | Mar 22 – Apr 5 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | Mar 22 – Apr 5 | — | 90–120 days | Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive. |
Date ranges are estimates based on university extension guidelines and this city's NOAA frost normals — not a guarantee. Scroll to see all columns on narrow screens.
Frequently Asked Questions
When is the last frost in Atascadero, CA?
Based on 1991–2020 NOAA climate normals for the PASO ROBLES, CA US station, the last spring frost in Atascadero typically falls around March 15. A cautious gardener might wait until April 13 (only a 10% chance of a later frost), while February 12 marks an earlier, higher-risk planting date.
When is the first frost in Atascadero, CA in fall?
The first fall frost in Atascadero typically arrives around November 10. To stay safe, assume frost could start as early as October 23; in milder years it can hold off until November 29.
How long is the growing season in Atascadero, CA?
Atascadero's average frost-free growing season is about 238 days, running from the typical last spring frost (March 15) to the typical first fall frost (November 10).
What USDA hardiness zone is Atascadero, CA in?
Atascadero, CA is in USDA plant hardiness zone 9a, per the USDA's 2023 Plant Hardiness Zone Map. Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.