When to plant in Denison, TX
USDA Zone 8aDenison, Texas frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Denison enjoys a long ~250-day frost-free season — you can succession-sow, fit in a second crop, and grow long-season heat-lovers with room to spare. Zone 8a means many perennials and even some tender shrubs overwinter in Denison, while your frost dates still decide when annuals go out.
Frost probability
SHERMAN · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Denison’s own odds, recorded at SHERMAN.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 15 | Mar 28 | Mar 8 | Oct 26 | Nov 9 | Nov 24 |
| 32°F | Apr 1 | Mar 14 | Feb 25 | Nov 2 | Nov 19 | Dec 6 |
| 28°F | Mar 21 | Mar 2 | Feb 10 | Nov 11 | Nov 30 | Dec 20 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Denison, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 32 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Denison planting FAQ
When is the last spring frost in Denison, TX?
Plan for the last spring frost in Denison around March 14 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Denison, TX?
In Denison, the first 32°F freeze of fall lands around November 19 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Denison in?
Denison is in USDA hardiness zone 8a. In zone 8a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Denison?
There are roughly 250 frost-free days in Denison (a long growing season), running from the average last frost around March 14 to the first fall frost near November 19.
When should I plant tomatoes in Denison?
In Denison, start tomato seeds indoors around January 17–January 31, then transplant seedlings outdoors around March 21 once the danger of frost has passed.
Never miss a window in Denison
An email when it’s time to start seeds, transplant, and sow — timed to Denison’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at SHERMAN, 9 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Denison, TX — Frost Dates & Zone 8a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00418274. Retrieved from https://blissgarden.com/texas/denison.