USDA hardiness zone lookup
San Antonio, TX — USDA Zone 9a
San Antonio, Texas · 272-day growing season
Frost dates and growing season in San Antonio
| USDA hardiness zone | Zone 9a |
|---|---|
| Average last spring frost | February 28 |
| Average first fall frost | November 27 |
| Growing season length | ~272 days |
| Temperature range (F) | 20 to 30°F |
| Temperature range (C) | -7 to -1°C |
San Antonio spans USDA zones 8 to 9 across its ZIP codes (Zone 8b, Zone 9a); the city center sits in Zone 9a, so warmer and cooler pockets exist either side of that.
These are 50%-probability averages modeled from San Antonio's USDA hardiness zone and regional climate normals — not a single-station reading. In a typical year the last spring frost will have passed by February 28, but a colder-than-average year can run 1-2 weeks later. Plant tender crops (tomatoes, peppers, basil) once both soil and night temperatures are consistently warm — a thermometer beats the calendar.
Growing season in San Antonio
San Antonio, Texas sits in USDA Zone 9a, with roughly 272 frost-free days between an average last spring frost around February 28 and a first fall frost around November 27. That is a near year-round season — the limiting factor is summer heat, not frost, so schedule cool-season crops for winter and protect tender ones from extreme highs. San Antonio lies near 29.4°N; higher-latitude gardens get longer midsummer days but a tighter shoulder season at this zone. As a large metro, the built-up core typically runs up to half a zone warmer than outlying suburbs through the urban heat-island effect — sheltered city gardens often push tender crops a little earlier than the average suggests.
What grows in San Antonio
San Antonio falls in USDA Zone 9a, so the same hardiness constraints apply as the full Zone 9 guide. Vegetables, herbs, and fruit trees rated to Zone 9a (or hardier) will overwinter here in a typical year.
- Tomatoes (year-round in many areas)
- Peppers (all year)
- Citrus (oranges, lemons, limes, grapefruit)
- Avocado
- Mango (warmer areas)
- Banana
- Sweet potatoes
- Okra
- Southern peas
- Pomegranates
What to plant in San Antonio this week
San Antonio is in high summer — most spring plantings are in. Keep an eye on watering and start planning your fall crop. Cool-season seedlings (broccoli, cabbage, lettuce) can be started indoors for a fall transplant.
- When to plant tomatoes in zone 9
- When to plant peppers in zone 9
- When to plant bush beans in zone 9
- When to plant cucumbers in zone 9
- When to plant basil in zone 9
Full planting calendar for San Antonio
Crop-by-crop sowing, transplant, and harvest dates calibrated to zone 9 averages:
- When to plant tomatoes in zone 9
- When to plant peppers in zone 9
- When to plant basil in zone 9
- When to plant garlic in zone 9
- When to plant lettuce in zone 9
- When to plant bush beans in zone 9
- When to plant cucumbers in zone 9
- When to plant summer squash in zone 9
- When to plant peas in zone 9
- When to plant carrots in zone 9
- When to plant broccoli in zone 9
- When to plant cauliflower in zone 9
- When to plant cabbage in zone 9
- When to plant kale in zone 9
- When to plant brussels sprouts in zone 9
- When to plant collard greens in zone 9
- When to plant spinach in zone 9
- When to plant swiss chard in zone 9
- When to plant arugula in zone 9
- When to plant beets in zone 9
- When to plant radishes in zone 9
- When to plant turnips in zone 9
- When to plant parsnips in zone 9
- When to plant kohlrabi in zone 9
- When to plant onions in zone 9
- When to plant leeks in zone 9
- When to plant celery in zone 9
- When to plant asparagus in zone 9
- When to plant potatoes in zone 9
- When to plant sweet potatoes in zone 9
- When to plant eggplant in zone 9
- When to plant okra in zone 9
- When to plant sweet corn in zone 9
- When to plant pumpkins in zone 9
- When to plant winter squash in zone 9
- When to plant zucchini in zone 9
- When to plant cantaloupe in zone 9
- When to plant watermelon in zone 9
- When to plant pole beans in zone 9
- When to plant edamame in zone 9
- When to plant cilantro in zone 9
- When to plant dill in zone 9
- When to plant parsley in zone 9
- When to plant oregano in zone 9
- When to plant thyme in zone 9
- When to plant sage in zone 9
- When to plant rosemary in zone 9
- When to plant chives in zone 9
ZIP codes in San Antonio
Drill down to the precise frost window and planting calendar for a specific ZIP in San Antonio:
- 78205 — San Antonio (Zone 9a)
- 78207 — San Antonio (West Side) (Zone 9a)
- 78228 — San Antonio (West) (Zone 9a)
- 78237 — San Antonio (Edgewood) (Zone 9a)
- 78240 — San Antonio (Northwest) (Zone 9a)
- 78250 — San Antonio (Far Northwest) (Zone 8b)
Local microclimate notes
Zone tables give you the average — but San Antonio gardens vary. South-facing walls and paved areas can run a full half-zone warmer than the published rating. Low-lying spots, frost pockets, and shaded north sides can run colder. If you've gardened here a few seasons, your own frost record — the last time you actually got frost damage — beats any national average.
Source and methodology
Hardiness zone from the USDA Plant Hardiness Zone Map (2023 revision). Frost-date and growing-season figures are modeled from San Antonio's USDA hardiness zone and regional NOAA 1991-2020 climate normals — zone-level estimates, not a per-station record, so treat them as planning guidance and confirm against your own local frost history. Crop recommendations draw on US Cooperative Extension references, curated by the Growli editorial team. Last reviewed June 2026.
Other cities in Texas
- Abilene, TX — USDA Zone 8a
- Allen, TX — USDA Zone 8a
- Arlington, TX — USDA Zone 8a
- Austin, TX — USDA Zone 8b
- Brownsville, TX — USDA Zone 10a
- Bryan, TX — USDA Zone 8b
- Carrollton, TX — USDA Zone 8a
- College Station, TX — USDA Zone 8b
- Conroe, TX — USDA Zone 9a
- Corpus Christi, TX — USDA Zone 9b
- Dallas, TX — USDA Zone 8b
- Del Rio, TX — USDA Zone 9a
- All of Texas by zone