When to plant in Columbine, CO
USDA Zone 6aColumbine, Colorado frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
Zone 6a means Columbine sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
MARSTON FLTR PLT · 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 Columbine’s own odds, recorded at MARSTON FLTR PLT.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 29 | May 12 | Apr 30 | Sep 17 | Oct 2 | Oct 15 |
| 32°F | May 17 | May 2 | Apr 20 | Sep 27 | Oct 11 | Oct 23 |
| 28°F | May 7 | Apr 23 | Apr 8 | Oct 6 | Oct 21 | Nov 5 |
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 Columbine, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 17 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.
Columbine planting FAQ
When is the last spring frost in Columbine, CO?
On average, the last spring frost in Columbine is around May 2 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Columbine, CO?
The first fall frost in Columbine typically arrives around October 11 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Columbine in?
Columbine is in USDA hardiness zone 6a. In zone 6a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Columbine?
There are roughly 162 frost-free days in Columbine (a moderate growing season), running from the average last frost around May 2 to the first fall frost near October 11.
When should I plant tomatoes in Columbine?
In Columbine, start tomato seeds indoors around March 7–March 21, then transplant seedlings outdoors around May 9 once the danger of frost has passed.
Never miss a window in Columbine
An email when it’s time to start seeds, transplant, and sow — timed to Columbine’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Ken Caryl · 4 km
- Littleton · 4 km
- Dakota Ridge · 7 km
- Englewood · 9 km
- Highlands Ranch · 10 km
- Lakewood · 13 km
- Greenwood Village · 14 km
- Centennial · 18 km
Frost dates recorded at MARSTON FLTR PLT, 4 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 Columbine, CO — Frost Dates & Zone 6a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00055402. Retrieved from https://blissgarden.com/colorado/columbine.