Fort Carson, CO planting zone & frost dates
Fort Carson is in USDA hardiness zone 6a. The last spring frost usually comes around May 3 and the first fall frost around October 8, for a growing season of about 158 days.
Planting calendar for Fort Carson
Dates are counted from the average last spring frost (May 3) 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: Mar 8 – Mar 22 Transplant outdoors: May 10 – May 17 |
| Peppers | Start seeds indoors: Feb 22 – Mar 8 Transplant outdoors: May 17 – May 24 |
| Eggplant | Start seeds indoors: Feb 22 – Mar 8 Transplant outdoors: May 17 – May 24 |
| Broccoli | Start seeds indoors: Feb 22 – Mar 8 Transplant outdoors: Apr 5 – Apr 19 |
| Cabbage | Start seeds indoors: Feb 22 – Mar 8 Transplant outdoors: Apr 5 – Apr 19 |
| Onions (sets) | Plant outdoors: Apr 5 – Apr 19 |
| Peas | Sow outdoors: Mar 22 – Apr 5 |
| Spinach | Sow outdoors: Mar 22 – Apr 5 |
| Lettuce | Sow outdoors: Apr 5 – Apr 19 |
| Carrots | Sow outdoors: Apr 5 – Apr 19 |
| Potatoes | Plant outdoors: Apr 5 – Apr 19 |
| Beans | Sow outdoors: May 10 – May 17 |
| Sweet corn | Sow outdoors: May 10 – May 17 |
| Cucumbers | Sow outdoors: May 10 – May 17 |
| Squash & zucchini | Sow outdoors: May 10 – May 17 |
| Basil | Start seeds indoors: Mar 22 – Apr 5 Transplant outdoors: May 10 – May 17 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 13 (8 weeks before the average first fall frost on Oct 8).
Useful for zone 6a 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
- Cold frame / mini greenhouse — adds weeks to a short season
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 22 | May 3 | May 15 |
| First 32°F frost in fall is before | Oct 19 | Oct 8 | Sep 26 |
How to read it: in spring there is a 10% chance of a frost after May 15, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 26. A hard freeze (28°F) usually ends around April 24.
Nearby cities
- Security-Widefield zone 6a, last frost May 3
- Colorado Springs zone 6a, last frost May 3
- Fountain zone 6a, last frost May 3
- Black Forest zone 5b, last frost May 9
- Pueblo West zone 6a, last frost Apr 26
- Pueblo zone 6a, last frost Apr 30
- Cañon City zone 6a, last frost May 4
- Castle Rock zone 5b, last frost May 9
Questions
What growing zone is Fort Carson, CO?
Fort Carson is in USDA Plant Hardiness Zone 6a (average extreme winter low -10°F to -5°F), according to the USDA 2023 map.
When is the last frost in Fort Carson?
The average last spring frost (32°F) in Fort Carson is May 3. There is still a 10% chance of frost until May 15.
When can I plant tomatoes in Fort Carson?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 10 – May 17. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Colorado Springs Muni Ap, CO (USW00093037), 11.9 km (7.4 mi) from the city center, elevation 1884 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.