Summer squash
What Plant Yet? knows about summer squash, and where each number comes from. For today's answer, pick your town.
Planting numbers
- Frost category
- Tender Source: Colorado State University Extension
- Plant outdoors
- 1 week after typical last frost Source: Colorado State University Extension
- Start seeds indoors
- 2–3 weeks before planting out Source: Colorado State University Extension
- Cover at or below
- 32°F Given for tender crops as a group. Source: Utah State University Extension
- Grows once daytime temperatures reach
- 55°F Source: Colorado State University Extension
- Days to harvest
- 50–65 Source: Colorado State University Extension
Left out because we found no university extension source for it: minimum night temperature. We don't estimate.
Growing tips
- Above 5,000 feet, summer squash and cucumbers are the most reliable vine crops because they mature quickly. (Colorado State University Extension)
- Harvest young, at about 6 inches long, for best quality. (Colorado State University Extension)
- Early flowers with no fruit are normal: male flowers appear before female ones. (Colorado State University Extension)
- For the biggest total harvest, do not let fruit get large on the vine. (Colorado State University Extension)
- Shelter young plants from cool spring winds. (Colorado State University Extension)
How the answer uses this
The planting window opens 1 week after typical last frost in your town and stays open while a planting still has 65 days to mature before the typical first fall frost. Inside the window the answer is Plant when the coldest of the next 7 nights stays above 32°F (no source gives a minimum night temperature, so the cold-damage temperature is used). Cover tonight shows when tonight's low is 32°F or colder while summer squash is normally in the ground.
Sources
- Colorado State University Extension — checked Nov 11, 2026
- Colorado State University Extension — checked Nov 11, 2026
- Utah State University Extension — checked Nov 11, 2026
- Colorado State University Extension — checked Nov 11, 2026
- Colorado State University Extension — checked Nov 11, 2026
Guidance only. Extension advice is written for typical conditions; your soil, variety and microclimate matter.