Denison, TX planting zone & frost dates
Denison is in USDA hardiness zone 8a. The last spring frost usually comes around March 14 and the first fall frost around November 19, for a growing season of about 250 days.
Planting calendar for Denison
Dates are counted from the average last spring frost (March 14) 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: Jan 17 – Jan 31 Transplant outdoors: Mar 21 – Mar 28 |
| Peppers | Start seeds indoors: Jan 3 – Jan 17 Transplant outdoors: Mar 28 – Apr 4 |
| Eggplant | Start seeds indoors: Jan 3 – Jan 17 Transplant outdoors: Mar 28 – Apr 4 |
| Broccoli | Start seeds indoors: Jan 3 – Jan 17 Transplant outdoors: Feb 14 – Feb 28 |
| Cabbage | Start seeds indoors: Jan 3 – Jan 17 Transplant outdoors: Feb 14 – Feb 28 |
| Onions (sets) | Plant outdoors: Feb 14 – Feb 28 |
| Peas | Sow outdoors: Jan 31 – Feb 14 |
| Spinach | Sow outdoors: Jan 31 – Feb 14 |
| Lettuce | Sow outdoors: Feb 14 – Feb 28 |
| Carrots | Sow outdoors: Feb 14 – Feb 28 |
| Potatoes | Plant outdoors: Feb 14 – Feb 28 |
| Beans | Sow outdoors: Mar 21 – Mar 28 |
| Sweet corn | Sow outdoors: Mar 21 – Mar 28 |
| Cucumbers | Sow outdoors: Mar 21 – Mar 28 |
| Squash & zucchini | Sow outdoors: Mar 21 – Mar 28 |
| Basil | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Mar 21 – Mar 28 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 24 (8 weeks before the average first fall frost on Nov 19).
Useful for zone 8a 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
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Feb 25 | Mar 14 | Apr 1 |
| First 32°F frost in fall is before | Dec 6 | Nov 19 | Nov 2 |
How to read it: in spring there is a 10% chance of a frost after April 1, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 2. A hard freeze (28°F) usually ends around March 2.
Hardiness zone by ZIP code in Denison
- 75020 zone 8a
- 75021 zone 8a
Nearby cities
Questions
What growing zone is Denison, TX?
Denison is in USDA Plant Hardiness Zone 8a (average extreme winter low 10°F to 15°F), according to the USDA 2023 map.
When is the last frost in Denison?
The average last spring frost (32°F) in Denison is March 14. There is still a 10% chance of frost until April 1.
When can I plant tomatoes in Denison?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 21 – Mar 28. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Sherman, TX (USC00418274), 11.3 km (7.0 mi) from the city center, elevation 232 m, based on 30 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.