When to plant zucchini & summer squash
Zucchini & Summer Squash are frost-tender: plant them out only after your last spring frost. Two or three plants feed a family; a second sowing in early summer dodges squash vine borers.
- Start seeds indoors 3–4 weeks before the last spring frost.
- Sow seeds outdoors 1–3 weeks after the last spring frost.
- For a fall crop, sow 8–10 weeks before the first fall frost.
About 50 days from planting to harvest.
Get exact dates for your garden
Planting dates by hardiness zone
| Zone | Typical last frost | Start indoors | Sow outdoors | Fall crop |
|---|---|---|---|---|
| 2a | May 24 | Apr 26 – May 3 | May 31 – Jun 14 | — |
| 3b | May 17 | Apr 19 – Apr 26 | May 24 – Jun 7 | Jul 16 – Jul 30 |
| 4a | May 12 | Apr 14 – Apr 21 | May 19 – Jun 2 | Jul 20 – Aug 3 |
| 4b | May 8 | Apr 10 – Apr 17 | May 15 – May 29 | Jul 23 – Aug 6 |
| 5a | May 3 | Apr 5 – Apr 12 | May 10 – May 24 | Jul 27 – Aug 10 |
| 5b | May 1 | Apr 3 – Apr 10 | May 8 – May 22 | Aug 2 – Aug 16 |
| 6a | Apr 29 | Apr 1 – Apr 8 | May 6 – May 20 | Aug 8 – Aug 22 |
| 6b | Apr 22 | Mar 25 – Apr 1 | Apr 29 – May 13 | Aug 13 – Aug 27 |
| 7a | Apr 16 | Mar 19 – Mar 26 | Apr 23 – May 7 | Aug 16 – Aug 30 |
| 7b | Apr 5 | Mar 8 – Mar 15 | Apr 12 – Apr 26 | Aug 23 – Sep 6 |
| 8a | Mar 29 | Mar 1 – Mar 8 | Apr 5 – Apr 19 | Aug 29 – Sep 12 |
| 8b | Mar 16 | Feb 16 – Feb 23 | Mar 23 – Apr 6 | Sep 5 – Sep 19 |
| 9a | Mar 3 | Feb 3 – Feb 10 | Mar 10 – Mar 24 | Sep 16 – Sep 30 |
| 9b | Feb 20 | Jan 23 – Jan 30 | Feb 27 – Mar 13 | Sep 26 – Oct 10 |
| 10a | Mar 2 | Feb 2 – Feb 9 | Mar 9 – Mar 23 | Sep 22 – Oct 6 |
Zone rows use the median frost dates of all ZIP codes in that zone. Zones measure winter cold, not season length, so two places in the same zone can have frost dates weeks apart — use your ZIP code for real dates.
When to plant zucchini & summer squash in major cities
| City | Median last frost | Start indoors | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Seattle, WA | Mar 13 | Feb 13 – Feb 20 | Mar 20 – Apr 3 | Sep 8 – Sep 22 |
| Portland, OR | Feb 25 | Jan 28 – Feb 4 | Mar 4 – Mar 18 | Sep 22 – Oct 6 |
| Salt Lake City, UT | Apr 25 | Mar 28 – Apr 4 | May 2 – May 16 | Aug 9 – Aug 23 |
| Denver, CO | Apr 30 | Apr 2 – Apr 9 | May 7 – May 21 | Aug 3 – Aug 17 |
| Minneapolis, MN | Apr 23 | Mar 26 – Apr 2 | Apr 30 – May 14 | Aug 7 – Aug 21 |
| Chicago, IL | Apr 10 | Mar 13 – Mar 20 | Apr 17 – May 1 | Aug 27 – Sep 10 |
| Detroit, MI | Apr 27 | Mar 30 – Apr 6 | May 4 – May 18 | Aug 16 – Aug 30 |
| Kansas City, MO | Apr 4 | Mar 7 – Mar 14 | Apr 11 – Apr 25 | Aug 24 – Sep 7 |
| Columbus, OH | Apr 20 | Mar 23 – Mar 30 | Apr 27 – May 11 | Aug 15 – Aug 29 |
| Boston, MA | Apr 4 | Mar 7 – Mar 14 | Apr 11 – Apr 25 | Aug 31 – Sep 14 |
| New York, NY | Mar 30 | Mar 2 – Mar 9 | Apr 6 – Apr 20 | Sep 11 – Sep 25 |
| Philadelphia, PA | Mar 30 | Mar 2 – Mar 9 | Apr 6 – Apr 20 | Sep 8 – Sep 22 |
| Washington, DC | Mar 29 | Mar 1 – Mar 8 | Apr 5 – Apr 19 | Aug 30 – Sep 13 |
| Charlotte, NC | Mar 30 | Mar 2 – Mar 9 | Apr 6 – Apr 20 | Aug 25 – Sep 8 |
| Nashville, TN | Apr 1 | Mar 4 – Mar 11 | Apr 8 – Apr 22 | Aug 22 – Sep 5 |
| Atlanta, GA | Mar 25 | Feb 25 – Mar 4 | Apr 1 – Apr 15 | Aug 31 – Sep 14 |
| Dallas, TX | Mar 2 | Feb 2 – Feb 9 | Mar 9 – Mar 23 | Sep 20 – Oct 4 |
Growing zucchini & summer squash: quick facts
| Frost tolerance | Very tender: damaged by frost and stalled by cold; plant once nights stay above 50°F |
|---|---|
| Soil temperature | at least 60°F to germinate; 70–95°F is ideal |
| Planting depth | 1 in |
| Spacing | 24–36 in |
| Germination | 3–10 days |
| Days to harvest | about 50 days from planting |
Typical figures from university extension planting guides. Seed packets give the best numbers for a specific variety.