Grand Junction, CO planting zone & frost dates
Grand Junction is in USDA hardiness zone 7a. The last spring frost usually comes around April 14 and the first fall frost around October 23, for a growing season of about 190 days.
Planting calendar for Grand Junction
Dates are counted from the average last spring frost (April 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: Feb 17 – Mar 3 Transplant outdoors: Apr 21 – Apr 28 |
| Peppers | Start seeds indoors: Feb 3 – Feb 17 Transplant outdoors: Apr 28 – May 5 |
| Eggplant | Start seeds indoors: Feb 3 – Feb 17 Transplant outdoors: Apr 28 – May 5 |
| Broccoli | Start seeds indoors: Feb 3 – Feb 17 Transplant outdoors: Mar 17 – Mar 31 |
| Cabbage | Start seeds indoors: Feb 3 – Feb 17 Transplant outdoors: Mar 17 – Mar 31 |
| Onions (sets) | Plant outdoors: Mar 17 – Mar 31 |
| Peas | Sow outdoors: Mar 3 – Mar 17 |
| Spinach | Sow outdoors: Mar 3 – Mar 17 |
| Lettuce | Sow outdoors: Mar 17 – Mar 31 |
| Carrots | Sow outdoors: Mar 17 – Mar 31 |
| Potatoes | Plant outdoors: Mar 17 – Mar 31 |
| Beans | Sow outdoors: Apr 21 – Apr 28 |
| Sweet corn | Sow outdoors: Apr 21 – Apr 28 |
| Cucumbers | Sow outdoors: Apr 21 – Apr 28 |
| Squash & zucchini | Sow outdoors: Apr 21 – Apr 28 |
| Basil | Start seeds indoors: Mar 3 – Mar 17 Transplant outdoors: Apr 21 – Apr 28 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 28 (8 weeks before the average first fall frost on Oct 23).
Useful for zone 7a 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
As an Amazon Associate, FrostZoneMap earns from qualifying purchases, at no extra cost to you.
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 1 | Apr 14 | Apr 28 |
| First 32°F frost in fall is before | Nov 6 | Oct 23 | Oct 11 |
How to read it: in spring there is a 10% chance of a frost after April 28, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 11. A hard freeze (28°F) usually ends around April 2.
Hardiness zone by ZIP code in Grand Junction
- 81501 zone 7a
- 81502 zone 7a
- 81503 zone 7a
- 81504 zone 7a
- 81505 zone 6b
- 81506 zone 7a
- 81507 zone 7a
Nearby cities
- Clifton zone 7a, last frost Apr 23
- Fruita zone 7a, last frost Apr 27
- Montrose zone 6b, last frost Apr 28
- Durango zone 6b, last frost May 21
- Edwards zone 5b, last frost Jun 6
- Steamboat Springs zone 4b, last frost Jun 9
- Cañon City zone 6a, last frost May 4
- Golden zone 6a, last frost May 3
Questions
What growing zone is Grand Junction, CO?
Grand Junction is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 6b.
When is the last frost in Grand Junction?
The average last spring frost (32°F) in Grand Junction is April 14. There is still a 10% chance of frost until April 28.
When can I plant tomatoes in Grand Junction?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 21 – Apr 28. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Grand Junction Wfo, CO (USC00053486), 6.6 km (4.1 mi) from the city center, elevation 1471 m, based on 8 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.