When to plant in Parker, CO
USDA Zone 5bEverything below — frost dates, hardiness zone, and what to plant when in Parker, Colorado — is derived from the closest NOAA station with complete climate normals.
Zone 5b means Parker sees real winter cold, but a good range of perennials survive; the frost dates above govern when annual vegetables go out.
Frost probability
PARKER · 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 Parker’s own odds, recorded at PARKER.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 2 | May 20 | May 8 | Sep 12 | Sep 25 | Oct 6 |
| 32°F | May 23 | May 9 | Apr 27 | Sep 21 | Oct 3 | Oct 15 |
| 28°F | May 12 | Apr 29 | Apr 15 | Sep 29 | Oct 12 | Oct 23 |
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 Parker, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 14 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.
Parker planting FAQ
When is the last spring frost in Parker, CO?
Plan for the last spring frost in Parker around May 9 (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 Parker, CO?
In Parker, the first 32°F freeze of fall lands around October 3 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Parker in?
Parker is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Parker?
There are roughly 147 frost-free days in Parker (a short growing season), running from the average last frost around May 9 to the first fall frost near October 3.
When should I plant tomatoes in Parker?
In Parker, start tomato seeds indoors around March 14–March 28, then transplant seedlings outdoors around May 16 once the danger of frost has passed.
Never miss a window in Parker
An email when it’s time to start seeds, transplant, and sow — timed to Parker’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- The Pinery · 7 km
- Lone Tree · 9 km
- Castle Pines · 9 km
- Centennial · 12 km
- Cherry Creek · 14 km
- Castle Rock · 16 km
- Greenwood Village · 17 km
- Highlands Ranch · 17 km
Frost dates recorded at PARKER, 2 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 Parker, CO — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00056323. Retrieved from https://blissgarden.com/colorado/parker.