Frost Dates & Planting Calendar for San Marcos, TX
Plan your garden around San Marcos, TX's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.
Last Spring Frost
February 28
Safe Mar 21
Typical Feb 28
Risky Feb 1
First Fall Frost
November 29
Safe Nov 8
Typical Nov 29
Risky Dec 21
Growing Season
273 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 SAN MARCOS, TX US, 0.8 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 3 – Jan 17 | — | Mar 7 – Mar 14 | — | 60–85 days | Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed. |
| Pepper | Dec 20 – Jan 3 | — | Mar 7 – Mar 21 | — | 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 | Dec 20 – Jan 3 | — | Mar 14 – Mar 21 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | Jan 31 – Feb 7 | Mar 7 – Mar 14 | Mar 7 – Mar 14 | — | 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 7 – Feb 14 | Mar 7 – Mar 21 | Mar 7 – Mar 14 | — | 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 | Jan 31 – Feb 7 | Mar 7 – Mar 21 | Mar 7 – Mar 14 | — | 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 7 – Mar 21 | — | — | 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 | Jan 31 – Feb 7 | — | Mar 14 – Mar 21 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | Jan 31 – Feb 7 | — | Mar 14 – Mar 21 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | Feb 28 – Mar 14 | — | — | 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 | — | Feb 28 – Mar 14 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Jan 17 – Jan 31 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | Jan 31 – Feb 14 | — | Oct 4 – Oct 18 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Jan 17 – Jan 31 | — | Oct 4 – Oct 18 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | Jan 31 – Feb 14 | — | Sep 20 – Oct 4 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | Jan 31 – Feb 14 | — | Oct 18 – Oct 25 | 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 7 – Feb 21 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Jan 10 – Jan 24 | — | Feb 7 – Feb 14 | Sep 27 – Oct 4 | 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 10 – Jan 24 | — | Feb 14 – Feb 21 | Sep 20 – Sep 27 | 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 10 – Jan 24 | — | Jan 31 – Feb 14 | Sep 20 – Oct 4 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Jan 10 – Jan 24 | — | Feb 7 – Feb 21 | — | 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 | — | Jan 31 – Feb 14 | — | Sep 6 – Sep 20 | 60–80 days | Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked. |
| Beet | — | Jan 31 – Feb 14 | — | Sep 20 – Oct 4 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Jan 24 – Feb 7 | — | Oct 18 – Nov 1 | 22–30 days | Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked. |
| Turnip | — | Jan 31 – Feb 14 | — | Sep 20 – Oct 4 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Dec 20 – Jan 3 | — | Jan 31 – Feb 14 | — | 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 | — | — | — | Nov 1 – Nov 15 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | Jan 31 – Feb 14 | — | — | 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 14 – Mar 28 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | Jan 31 – Feb 14 | — | 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 | Jan 17 – Jan 24 | — | Mar 7 – Mar 14 | — | 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 7 – Feb 21 | — | Oct 4 – Oct 18 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Jan 3 – Jan 17 | — | Feb 14 – Feb 21 | — | 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 7 – Feb 21 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Jan 3 – Jan 17 | — | Feb 28 – Mar 7 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Jan 3 – Jan 17 | — | Feb 28 – Mar 7 | — | 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 7 – Mar 21 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | Jan 31 – Feb 7 | Mar 7 – Mar 21 | Mar 7 – Mar 14 | — | 60–70 days | Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms. |
| Marigold | Jan 17 – Jan 31 | — | Mar 7 – Mar 14 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | Jan 31 – Feb 7 | Mar 7 – Mar 21 | Mar 7 – Mar 14 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | Mar 7 – Mar 21 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | Mar 7 – Mar 21 | — | 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 San Marcos, TX?
Based on 1991–2020 NOAA climate normals for the SAN MARCOS, TX US station, the last spring frost in San Marcos typically falls around February 28. A cautious gardener might wait until March 21 (only a 10% chance of a later frost), while February 1 marks an earlier, higher-risk planting date.
When is the first frost in San Marcos, TX in fall?
The first fall frost in San Marcos typically arrives around November 29. To stay safe, assume frost could start as early as November 8; in milder years it can hold off until December 21.
How long is the growing season in San Marcos, TX?
San Marcos's average frost-free growing season is about 273 days, running from the typical last spring frost (February 28) to the typical first fall frost (November 29).
What USDA hardiness zone is San Marcos, TX in?
San Marcos, TX 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.