When to Plant Squash (Summer) in Colorado
Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.
Colorado spans USDA hardiness zones 3b, 4a, 4b, 5a, 5b, 6a, 6b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.
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Click your county for exact Squash (Summer) planting dates based on your local frost dates.
Hover over a county to see details. Click to view planting guide.
Squash (Summer) Planting Calendar for Colorado
▸ Zone 3b ~135 day growing season · Full guide →
Last frost: May 10 · First frost: September 22 · 135 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 29 | Mar 29 – Apr 12 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 24 | May 24 – Jun 14 |
| Harvest | July 19 | Jul 19 – Sep 20 |
▸ Zone 4a ~145 day growing season · Full guide →
Last frost: May 6 · First frost: September 28 · 145 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 25 | Mar 25 – Apr 8 |
| Transplant Outdoors | May 27 | May 27 – Jun 10 |
| Direct Sow | May 20 | May 20 – Jun 10 |
| Harvest | July 15 | Jul 15 – Sep 16 |
▸ Zone 4b ~155 day growing season · Full guide →
Last frost: May 1 · First frost: October 3 · 155 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Harvest | July 10 | Jul 10 – Sep 11 |
▸ Zone 5a ~166 day growing season · Full guide →
Last frost: April 25 · First frost: October 8 · 166 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | May 2 | May 2 – May 23 |
| Harvest | June 27 | Jun 27 – Aug 29 |
▸ Zone 5b ~178 day growing season · Full guide →
Last frost: April 18 · First frost: October 13 · 178 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | June 20 | Jun 20 – Aug 22 |
▸ Zone 6a ~193 day growing season · Full guide →
Last frost: April 10 · First frost: October 20 · 193 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 24 | Apr 24 – May 8 |
| Direct Sow | April 17 | Apr 17 – May 8 |
| Harvest | June 12 | Jun 12 – Aug 14 |
▸ Zone 6b ~205 day growing season · Full guide →
Last frost: April 3 · First frost: October 25 · 205 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | April 17 | Apr 17 – May 1 |
| Direct Sow | April 10 | Apr 10 – May 1 |
| Harvest | June 5 | Jun 5 – Aug 7 |
Growing Tips for Colorado
Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.
Squash (Summer) in Other States
- Alabama
- Alaska
- Alberta
- Arizona
- Arkansas
- British Columbia
- California
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Manitoba
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Brunswick
- New Hampshire
- New Jersey
- New Mexico
- New York
- Newfoundland and Labrador
- North Carolina
- North Dakota
- Northwest Territories
- Nova Scotia
- Nunavut
- Ohio
- Oklahoma
- Ontario
- Oregon
- Pennsylvania
- Prince Edward Island
- Quebec
- Rhode Island
- Saskatchewan
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
- Yukon
Frequently Asked Questions
When should I plant Squash (Summer) in Colorado?
Planting dates for Squash (Summer) in Colorado depend on your USDA zone. Colorado spans zones 3b, 4a, 4b, 5a, 5b, 6a, 6b. Check the planting calendar above for your specific zone's frost dates and planting windows.
What zone is Colorado for planting?
Colorado contains USDA hardiness zones 3b, 4a, 4b, 5a, 5b, 6a, 6b. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.