San Antonio, TX 78215 planting calendar
- USDA zone
- 9a20 to 25 °F
- Last frost
- Feb 25avg, 32°F
- First frost
- Nov 28avg, 32°F
- Growing season
- 277days
San Antonio, Texas is in USDA plant hardiness zone 9a. Its average last spring frost is around February 25 and the first fall frost around November 28, giving a growing season of about 277 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.
San Antonio planting calendar
Each crop's windows are counted from San Antonio'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 14 | Mar 4 – Mar 11 | May 3 – May 23 | — |
| Pepper | Very tender | Jan 1 | Mar 11 – Mar 18 | May 10 – Jun 9 | — |
| Cucumber | Tender | Jan 28 – Feb 4 | Mar 4 – Mar 11 | Apr 23 – May 13 | — |
| Summer squash / zucchini | Tender | — | Mar 4 – Mar 11 | Apr 18 – May 3 | — |
| Bush bean | Tender | — | Mar 4 – Mar 11 | Apr 23 – May 3 | Sep 29 – Oct 9 |
| Sweet corn | Tender | — | Feb 25 – Mar 11 | Apr 26 – May 26 | — |
| Basil | Very tender | Jan 14 – Jan 28 | Mar 4 – Mar 11 | Apr 3 – Apr 18 | — |
| Lettuce | Half-hardy | Jan 14 – Jan 28 | Jan 28 – Feb 11 | Mar 14 – Mar 29 | Sep 15 – Sep 30 |
| Pea | Hardy | — | Jan 14 – Jan 28 | Mar 10 – Mar 25 | Sep 5 – Sep 20 |
| Spinach | Hardy | — | Jan 14 – Jan 28 | Feb 23 – Mar 5 | Sep 25 – Oct 5 |
| Carrot | Half-hardy | — | Feb 4 – Feb 11 | Apr 5 – Apr 25 | Aug 26 – Sep 15 |
| Broccoli | Half-hardy | Jan 1 – Jan 14 | Jan 28 – Feb 11 | Mar 24 – Apr 13 | Aug 31 – Sep 20 |
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 USC00417947. 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 10 | Apr 2 | Nov 16 | Dec 3 | 251 |
| 32°F (freeze) | Feb 25 | Mar 19 | Nov 28 | Dec 21 | 277 |
| 28°F | Feb 5 | Mar 5 | Dec 15 | Jan 20 | 315 |
| 24°F | Jan 22 | Feb 25 | Jan 1 | Feb 4 | 355 |
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) | 7,164 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 10,618 | cool-season crops (brassicas, greens) |
Hardiness zone 9a
San Antonio sits in USDA plant hardiness zone 9a on the 2023 map — meaning its average annual extreme minimum winter temperature is about 20 to 25 °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 9a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is San Antonio?
- San Antonio, Texas is in USDA plant hardiness zone 9a on the 2023 map (average annual extreme minimum temperature 20 to 25 °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 San Antonio?
- The average (median) last spring frost at 32°F is around February 25, 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 19, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in San Antonio?
- The average first fall frost at 32°F is around November 28. That leaves a growing season of about 277 days between the average last spring and first fall frosts.
- When should I start tomatoes in San Antonio?
- Start tomato seeds indoors about Jan 1 – Jan 14 and transplant them outside about Mar 4 – Mar 11, once the danger of frost has passed. Estimated first harvest is around May 3 – May 23.
- How long is the growing season in San Antonio?
- About 277 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~February 25) and the average first fall frost (~November 28). 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 USC00417947 (San Antonio Incarnate Word, 3.4 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.