When to plant zucchini and summer squash
Short answer
Zucchini and summer squash are tender: seeds can go in around your average last frost. Start seeds indoors 2–3 weeks before you plant them outside. Seeds need soil of at least 60 °F to sprout.[1, 2]
Zucchini and summer squash at a glance
| Frost tolerance | Tender [1, 2] |
|---|---|
| Plant outside (seeds) | Around the average last frost [1, 2] |
| Start seeds indoors | 2–3 weeks before planting out [1] |
| Soil temperature for seeds | At least 60 °F; best around 90 °F [1] |
| Time to harvest | About 50 days [1] |
Spring planting
- Spring, seeds: Sow seed around the average last frost date. These crops don’t tolerate frost. [1, 2]
- Spring, transplants: Without frost protection, wait until the risk of frost is over. [1]
Example dates for some US cities
Based on each city's main airport weather station: the date with an even chance of frost after it (32 °F). [3] Your own dates can differ: use the ZIP code box above.
| City | Average last frost | Plant outside | Start indoors |
|---|---|---|---|
| New York, NY | Mar 30 | around Mar 30 | Mar 9 – Mar 16 |
| Atlanta, GA | Mar 15 | around Mar 15 | Feb 22 – Mar 1 |
| Dallas–Fort Worth, TX | Mar 8 | around Mar 8 | Feb 15 – Feb 22 |
| Chicago, IL | Apr 16 | around Apr 16 | Mar 26 – Apr 2 |
| Denver, CO | May 5 | around May 5 | Apr 14 – Apr 21 |
| Minneapolis, MN | Apr 23 | around Apr 23 | Apr 2 – Apr 9 |
| Seattle, WA | Mar 2 | around Mar 2 | Feb 9 – Feb 16 |
Questions people ask
When should I start zucchini and summer squash seeds indoors?
2–3 weeks before you plant them outside. Count back from your planting date: around your average last frost. [1, 2]
Can zucchini and summer squash survive frost?
No. Tender crops don’t tolerate frost, so plant around your average last frost date or later. [1]
What soil temperature do zucchini and summer squash seeds need?
At least 60 °F; they sprout best around 90 °F. [1]
How long do zucchini and summer squash take to grow?
About 50 days. [1]
Sources
Facts on this page were checked against these sources on November 6, 2026. The wording is our own. Frost dates: NOAA NCEI, U.S. Climate Normals 1991–2020; NOAA does not endorse this site. Some guides are written for Utah: we use only their general rules, not their local calendar dates.
- Vegetable Planting Guide (CMG GardenNotes #720). Colorado State University Extension. Reviewed Sep 2024.
- Suggested Vegetable Planting Dates for Utah. Utah State University Extension. Revised May 2025.
- U.S. Climate Normals 1991–2020 (frost dates). NOAA National Centers for Environmental Information.
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