Blanca, CO frost dates
Last spring frostMay 25median date
First fall frostSep 22median date
Growing season120 daysfrost-free
Hardiness zone5aZone 5a
How Blanca compares
- In 8 years out of 10, the last spring frost in Blanca falls between May 11 and June 12, a 32-day window. The first fall frost falls between September 10 and October 3.
- The median last frost is 14 days later than the Colorado median of May 11.
- Its 120-day growing season is longer than 29% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 22 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 215 nights a year at or below 32°F.
- Compared with Pueblo, CO, 120 km away, the last frost here is 25 days later than there and the growing season is 42 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 11 |
| 50% (median) | May 25 |
| 10% (safe for tender plants) | June 12 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 10 |
| 50% (median) | September 22 |
| 90% (late) | October 3 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Blanca, CO
Blanca, CO frost dates — last frost May 25, first frost Sep 22, zone 5a. whenisthelastfrost.com
Crop
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Start indoors: Mar 2 to Mar 16Transplant outside: Apr 27 to May 11
Start indoors: Mar 16 to Mar 30Transplant outside: Jun 8 to Jun 22
Start indoors: Mar 16 to Mar 30Transplant outside: Jun 8 to Jun 22
Start indoors: Mar 30 to Apr 13Transplant outside: Jun 1 to Jun 15
Start indoors: Mar 30 to Apr 13Transplant outside: May 4 to May 18Sow outdoors: Apr 27 to Jun 1Plant for fall: Jul 28 to Aug 25
Start indoors: Mar 30 to Apr 13Transplant outside: Apr 27 to May 11Sow outdoors: Apr 27 to May 11Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 30 to Apr 13Transplant outside: May 11 to May 25Plant for fall: Jun 16 to Jul 7
Start indoors: Mar 30 to Apr 13Transplant outside: May 4 to May 18Plant for fall: Jun 16 to Jul 7
Start indoors: Mar 30 to Apr 13Transplant outside: May 11 to May 25Plant for fall: Jun 16 to Jul 7
Start indoors: Apr 13 to Apr 27Transplant outside: Jun 15 to Jun 29Sow outdoors: Jun 15 to Jun 29
Start indoors: Apr 13 to Apr 27Transplant outside: Jun 1 to Jun 15
Sow outdoors: Apr 13 to May 4Plant for fall: Jun 30 to Jul 21
Sow outdoors: Apr 13 to May 4Plant for fall: Jul 28 to Aug 18
Sow outdoors: Apr 20 to Jun 1Plant for fall: Aug 11 to Sep 1
Start indoors: Apr 27 to May 4Transplant outside: Jun 8 to Jun 15Sow outdoors: Jun 1 to Jun 15Plant for fall: Jul 7 to Jul 21
Start indoors: Apr 27 to May 4Sow outdoors: Jun 1 to Jun 15Plant for fall: Jul 14 to Jul 28
Start indoors: Apr 27 to May 4Sow outdoors: Jun 1 to Jun 15
Start indoors: Apr 27 to May 4Transplant outside: Jun 8 to Jun 22
Sow outdoors: May 4 to Jun 1Plant for fall: Jun 30 to Jul 14
Sow outdoors: May 4 to Jun 1Plant for fall: Jul 14 to Jul 28
Sow outdoors: May 4 to May 25
Sow outdoors: May 11 to Jun 8Plant for fall: Jul 14 to Jul 28
Sow outdoors: May 11 to Jun 1Plant for fall: Jul 28 to Aug 18
Sow outdoors: Jun 1 to Jun 22Plant for fall: Jul 7 to Jul 21
Sow outdoors: Jun 1 to Jun 15
Transplant outside: Jun 8 to Jun 29
Plant for fall: Sep 8 to Oct 13
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Blanca, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 2 – Mar 16 | Apr 27 – May 11 | — | — |
| Peppers | Mar 16 – Mar 30 | Jun 8 – Jun 22 | — | — |
| Eggplant | Mar 16 – Mar 30 | Jun 8 – Jun 22 | — | — |
| Tomatoes | Mar 30 – Apr 13 | Jun 1 – Jun 15 | — | — |
| Lettuce | Mar 30 – Apr 13 | May 4 – May 18 | Apr 27 – Jun 1 | Jul 28 – Aug 25 |
| Kale | Mar 30 – Apr 13 | Apr 27 – May 11 | Apr 27 – May 11 | Jul 14 – Aug 4 |
| Broccoli | Mar 30 – Apr 13 | May 11 – May 25 | — | Jun 16 – Jul 7 |
| Cabbage | Mar 30 – Apr 13 | May 4 – May 18 | — | Jun 16 – Jul 7 |
| Cauliflower | Mar 30 – Apr 13 | May 11 – May 25 | — | Jun 16 – Jul 7 |
| Okra | Apr 13 – Apr 27 | Jun 15 – Jun 29 | Jun 15 – Jun 29 | — |
| Basil | Apr 13 – Apr 27 | Jun 1 – Jun 15 | — | — |
| Peas | — | — | Apr 13 – May 4 | Jun 30 – Jul 21 |
| Spinach | — | — | Apr 13 – May 4 | Jul 28 – Aug 18 |
| Radishes | — | — | Apr 20 – Jun 1 | Aug 11 – Sep 1 |
| Cucumbers | Apr 27 – May 4 | Jun 8 – Jun 15 | Jun 1 – Jun 15 | Jul 7 – Jul 21 |
| Zucchini & Summer Squash | Apr 27 – May 4 | — | Jun 1 – Jun 15 | Jul 14 – Jul 28 |
| Winter Squash & Pumpkins | Apr 27 – May 4 | — | Jun 1 – Jun 15 | — |
| Melons & Watermelon | Apr 27 – May 4 | Jun 8 – Jun 22 | — | — |
| Carrots | — | — | May 4 – Jun 1 | Jun 30 – Jul 14 |
| Beets | — | — | May 4 – Jun 1 | Jul 14 – Jul 28 |
| Potatoes | — | — | May 4 – May 25 | — |
| Swiss Chard | — | — | May 11 – Jun 8 | Jul 14 – Jul 28 |
| Cilantro | — | — | May 11 – Jun 1 | Jul 28 – Aug 18 |
| Green Beans | — | — | Jun 1 – Jun 22 | Jul 7 – Jul 21 |
| Sweet Corn | — | — | Jun 1 – Jun 15 | — |
| Sweet Potatoes | — | Jun 8 – Jun 29 | — | — |
| Garlic | — | — | — | Sep 8 – Oct 13 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Blanca 4 Nw, CO weather station, 7 km away (elevation 7,710 ft (2,350 m)).
Frost dates near Blanca
- Fort Garland May 25 · Sep 22
- Alamosa May 30 · Sep 17
- Chama May 31 · Sep 23
- Mosca May 30 · Sep 17
- San Luis May 31 · Sep 23
- Sanford May 28 · Sep 21
- La Veta May 6 · Oct 4
- Hooper May 24 · Sep 24
- La Jara May 28 · Sep 21
- Manassa May 28 · Sep 21
Frequently asked questions
When is the last frost in Blanca, CO?
The median last spring frost in Blanca, CO is May 25. There is still about a 10% chance of frost after June 12, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Blanca, CO?
The median first fall frost is September 22, with about a 10% chance of frost before September 10.
How long is the growing season in Blanca, CO?
About 120 days between the median last spring frost and first fall frost.
What planting zone is Blanca, CO?
Blanca, CO is in USDA hardiness zone 5a.