Alton, TX planting zone & frost dates
Alton is in USDA hardiness zone 10a. The last spring frost usually comes around January 23 and the first fall frost around December 28, for a growing season of about 340 days.
Planting calendar for Alton
Dates are counted from the average last spring frost (January 23) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Jan 30 – Feb 6 |
| Peppers | Start seeds indoors: Nov 14 – Nov 28 Transplant outdoors: Feb 6 – Feb 13 |
| Eggplant | Start seeds indoors: Nov 14 – Nov 28 Transplant outdoors: Feb 6 – Feb 13 |
| Broccoli | Start seeds indoors: Nov 14 – Nov 28 Transplant outdoors: Dec 26 – Jan 9 |
| Cabbage | Start seeds indoors: Nov 14 – Nov 28 Transplant outdoors: Dec 26 – Jan 9 |
| Onions (sets) | Plant outdoors: Dec 26 – Jan 9 |
| Peas | Sow outdoors: Dec 12 – Dec 26 |
| Spinach | Sow outdoors: Dec 12 – Dec 26 |
| Lettuce | Sow outdoors: Dec 26 – Jan 9 |
| Carrots | Sow outdoors: Dec 26 – Jan 9 |
| Potatoes | Plant outdoors: Dec 26 – Jan 9 |
| Beans | Sow outdoors: Jan 30 – Feb 6 |
| Sweet corn | Sow outdoors: Jan 30 – Feb 6 |
| Cucumbers | Sow outdoors: Jan 30 – Feb 6 |
| Squash & zucchini | Sow outdoors: Jan 30 – Feb 6 |
| Basil | Start seeds indoors: Dec 12 – Dec 26 Transplant outdoors: Jan 30 – Feb 6 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Nov 2 (8 weeks before the average first fall frost on Dec 28).
Useful for zone 10a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Dec 22 | Jan 23 | Feb 27 |
| First 32°F frost in fall is before | Feb 1 | Dec 28 | Dec 2 |
How to read it: in spring there is a 10% chance of a frost after February 27, so that is a safe date for tender plants. In fall there is a 10% chance of frost before December 2. A hard freeze (28°F) usually ends around January 7.
Nearby cities
Questions
What growing zone is Alton, TX?
Alton is in USDA Plant Hardiness Zone 10a (average extreme winter low 30°F to 35°F), according to the USDA 2023 map.
When is the last frost in Alton?
The average last spring frost (32°F) in Alton is January 23. There is still a 10% chance of frost until February 27.
When can I plant tomatoes in Alton?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 30 – Feb 6. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station La Joya, TX (USC00414911), 4.1 km (2.5 mi) from the city center, elevation 65 m, based on 20 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.