§ When to plant · Colorado · Checked Sept 2026
In Denver, tender crops like tomatoes and peppers can go out around May 15, and frost has historically passed 9 years in 10 by May 26. Cool-season crops go in from February, and again from July for fall.
Get a lifelong price reduction if you join Early Access. iPhone and Android, in the contiguous U.S.
§ 010 · Frost dates
Based on NOAA's 1991–2020 station records, with adjustments for tender crops.
| City · NOAA station | Last frost, on average | Plant tender crops from | Frost is over, 9 of 10 years by | Fall frost possible from |
|---|---|---|---|---|
| ArvadaWHEAT RIDGE 2 · 7 km | May 5 | May 18May 18 | May 31 | Sep 20 |
| AuroraCHERRY CREEK DAM · 13 km | May 7 | May 20May 20 | Jun 1 | Sep 25 |
| BoulderBOULDER · 4 km | May 6 | May 20May 20 | Jun 2 | Sep 21 |
| BroomfieldNORTHGLENN · 7 km | May 2 | May 14May 14 | May 26 | Sep 26 |
| Castle RockCASTLE ROCK · 6 km | May 9 | May 23May 23 | Jun 6 | Sep 17 |
| CentennialDENVER CENTENNIAL AIRPORT · 3 km | May 5 | May 18May 18 | May 30 | Sep 25 |
| Colorado SpringsCOLORADO SPRINGS MUNICIPAL AIRPORT · 9 km | May 3 | May 15May 15 | May 26 | Sep 26 |
| Commerce CityBRIGHTON 3 SOUTHEAST · 8 km | May 3 | May 15May 15 | May 27 | Sep 26 |
| DenverDENVER-STAPLETON · 1 km | May 4 | May 15May 15 | May 26 | Sep 25 |
| Fort CollinsFORT COLLINS · 4 km | May 2 | May 14May 14 | May 26 | Sep 24 |
| Grand JunctionGRAND JUNCTION WFO · 5 km | Apr 14 | Apr 27April 27 | May 9 | Oct 11 |
| GreeleyGREELEY UNC · 6 km | May 2 | May 14May 14 | May 26 | Sep 26 |
| LakewoodLAKEWOOD · 6 km | May 3 | May 16May 16 | May 29 | Sep 24 |
| LittletonMARSTON FLTR PLT · 5 km | May 2 | May 16May 16 | May 29 | Sep 27 |
| LongmontLONGMONT 2 ESE · 2 km | May 7 | May 20May 20 | Jun 2 | Sep 23 |
| LovelandLOVELAND 2N · 3 km | May 10 | May 23May 23 | Jun 4 | Sep 15 |
| ParkerPARKER · 6 km | May 9 | May 21May 21 | Jun 2 | Sep 21 |
| PuebloWFO PUEBLO · 8 km | Apr 30 | May 12May 12 | May 23 | Sep 28 |
| ThorntonNORTHGLENN · 6 km | May 2 | May 14May 14 | May 26 | Sep 26 |
| WestminsterNORTHGLENN · 5 km | May 2 | May 14May 14 | May 26 | Sep 26 |
Colorado's 20 largest cities (U.S. Census Bureau 2025 estimates), A to Z, each with its nearest NOAA station and the distance to it. Search any town to get its nearest station. "Plant tender crops from" is halfway between the average last frost and the date frost is over 9 years in 10; if frost is in the forecast after it, wait until it passes and nights stay above 36°F.
§ 020 · What to plant
Planting windows from Colorado's Cooperative Extension Service. Filter by season or crop group; every view has its own link.
Link to this view getezina.com/when-to-plant/colorado/
§ 030 · Crop by crop
Each crop has its own link, like #asparagus. Tender crops wait for the frost dates above; succession crops are sown again every few weeks for a steady harvest.
Asparagus officinalis
Perennial
Plant April.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Beta vulgaris
Cool seasonSuccession sow
Sow April.
Ready in about 58 days; sow again every 6 weeks.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Start seed indoors March; Set out transplants April.
Ready in about 95 days from seed, 65 from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Sow July to September.
Ready in about 130 days from seed, 100 from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Set out transplants May to April; Sow July.
Ready in about 110 days from seed, 80 from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Daucus carota
Cool seasonSuccession sow
Sow April, and again May to August, and again June.
Ready in about 70 days; sow again every 7 weeks.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Start seed indoors March.
Ready in about 95 days from seed, 68 from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Apium graveolens
Cool season
Start seed indoors February.
Ready in about 90 days from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Sow August to May.
Ready in about 65 days from seed, 55 from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Lactuca sativa
Cool season
Sow August.
Ready in about 45 days from seed, 30 from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Allium cepa
Cool season
Set out transplants April to May.
Ready in about 110 days from seed, 95 from transplants.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Pisum sativum
Cool seasonSuccession sow
Sow July, and again August.
Ready in about 65 days; sow again every 5 weeks.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Solanum tuberosum
Cool season
Plant April.
Ready in about 100 days.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Rheum rhabarbarum
Perennial
Plant May.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
Spinacia oleracea
Cool seasonSuccession sow
Sow June.
Ready in about 42 days; sow again every 5 weeks.
Source: Colorado State University Extension (Grow & Give program), Colorado Vegetable Guide — A guide for the backyard vegetable garden, covering all regions of Colorado. Days to harvest: Ezina crop catalog, from state extension guides.
§ 040 · Questions
On average from about April 14 in Grand Junction to May 10 in Loveland. Frost is over 9 years in 10 by May 9 to June 6.
The extension calendar lists cabbage, collards for October.
The latest fall windows on the calendar close in September. Filter by Fall above to see what is still open.
A zone is the coldest winter night, not a frost date. These dates come from NOAA station records and the extension service.
Yes. Run Ezina Dig on your address and your bed plans are dated from that site's own frost records, on iPhone and Android in the contiguous U.S.