US Grow Zones

When to plant zucchini & summer squash by zone

Last updated · Sources: NOAA NCEI 1991–2020 Climate Normals frost dates; timing rules described in our methodology

Cucurbita pepo is a warm-season crop that is tender to frost. Rule of thumb: start seeds indoors 3–4 weeks before the last frost; plant out from 1 week after to 3 weeks after the last frost; direct sow from 1 week after to 4 weeks after the last frost; for a fall crop, sow or plant 10–12 weeks before the first fall frost.

SeasonWarmtender to frost
Days to maturity45–60from sowing
Min. soil temp65°F18.3°C, at planting
Spacing24–36 inin the row

Zucchini & Summer Squash planting dates by zone

Each row uses the median 30%-risk frost dates of the major cities in that zone; rows marked * have no major city and use the median of NOAA stations in that zone instead. Frost dates vary a lot within a zone, so use your city page for local dates. In frost-free climates: Feb 15 – Apr 15; Aug 1 – Sep 15.

Zucchini & Summer Squash planting windows by hardiness zoneZucchini & Summer Squash planting windows by USDA zone. zone 1a: indoor May 1–May 8, transplant Jun 5–Jun 19, direct Jun 5–Jun 26; zone 1b: indoor May 1–May 8, transplant Jun 5–Jun 19, direct Jun 5–Jun 26; zone 2a: indoor Apr 23–Apr 30, transplant May 28–Jun 11, direct May 28–Jun 18; zone 2b: indoor Apr 22–Apr 29, transplant May 27–Jun 10, direct May 27–Jun 17; zone 3a: indoor May 7–May 14, transplant Jun 11–Jun 25, direct Jun 11–Jul 2; zone 3b: indoor Apr 26–May 3, transplant May 31–Jun 14, direct May 31–Jun 21, fall Jun 26–Jul 10; zone 4a: indoor Apr 14–Apr 21, transplant May 19–Jun 2, direct May 19–Jun 9, fall Jul 5–Jul 19; zone 4b: indoor Apr 7–Apr 14, transplant May 12–May 26, direct May 12–Jun 2, fall Jul 12–Jul 26; zone 5a: indoor Apr 6–Apr 13, transplant May 11–May 25, direct May 11–Jun 1, fall Jul 11–Jul 25; zone 5b: indoor Apr 6–Apr 13, transplant May 11–May 25, direct May 11–Jun 1, fall Jul 17–Jul 31; zone 6a: indoor Apr 6–Apr 13, transplant May 11–May 25, direct May 11–Jun 1, fall Jul 17–Jul 31; zone 6b: indoor Mar 29–Apr 5, transplant May 3–May 17, direct May 3–May 24, fall Jul 29–Aug 12; zone 7a: indoor Mar 25–Apr 1, transplant Apr 29–May 13, direct Apr 29–May 20, fall Jul 29–Aug 12; zone 7b: indoor Mar 13–Mar 20, transplant Apr 17–May 1, direct Apr 17–May 8, fall Aug 4–Aug 18; zone 8a: indoor Mar 4–Mar 11, transplant Apr 8–Apr 22, direct Apr 8–Apr 29, fall Aug 11–Aug 25; zone 8b: indoor Feb 22–Mar 1, transplant Mar 29–Apr 12, direct Mar 29–Apr 19, fall Aug 18–SJanFebMarAprMayJunJulAugSepOctNovDec1a*1b*2a2b*3a*3b*4a4b5a5b6a6b7a7b8a8b9a9b10a10b11a11b*12a*12b13a*13b*Start indoorsPlant outDirect sowFall cropFrost-free climate window · * estimated zone
Planting windows by zone, drawn from the table below. Zones marked * have no major city on this site and use NOAA station estimates.
ZoneMedian last frostStart indoorsTransplant / plant outDirect sowFall crop
1a*May 29May 1 – May 8Jun 5 – Jun 19Jun 5 – Jun 26—
1b*May 29May 1 – May 8Jun 5 – Jun 19Jun 5 – Jun 26—
2aMay 21Apr 23 – Apr 30May 28 – Jun 11May 28 – Jun 18—
2b*May 20Apr 22 – Apr 29May 27 – Jun 10May 27 – Jun 17—
3a*Jun 4May 7 – May 14Jun 11 – Jun 25Jun 11 – Jul 2—
3b*May 24Apr 26 – May 3May 31 – Jun 14May 31 – Jun 21Jun 26 – Jul 10
4aMay 12Apr 14 – Apr 21May 19 – Jun 2May 19 – Jun 9Jul 5 – Jul 19
4bMay 5Apr 7 – Apr 14May 12 – May 26May 12 – Jun 2Jul 12 – Jul 26
5aMay 4Apr 6 – Apr 13May 11 – May 25May 11 – Jun 1Jul 11 – Jul 25
5bMay 4Apr 6 – Apr 13May 11 – May 25May 11 – Jun 1Jul 17 – Jul 31
6aMay 4Apr 6 – Apr 13May 11 – May 25May 11 – Jun 1Jul 17 – Jul 31
6bApr 26Mar 29 – Apr 5May 3 – May 17May 3 – May 24Jul 29 – Aug 12
7aApr 22Mar 25 – Apr 1Apr 29 – May 13Apr 29 – May 20Jul 29 – Aug 12
7bApr 10Mar 13 – Mar 20Apr 17 – May 1Apr 17 – May 8Aug 4 – Aug 18
8aApr 1Mar 4 – Mar 11Apr 8 – Apr 22Apr 8 – Apr 29Aug 11 – Aug 25
8bMar 22Feb 22 – Mar 1Mar 29 – Apr 12Mar 29 – Apr 19Aug 18 – Sep 1
9aMar 11Feb 11 – Feb 18Mar 18 – Apr 1Mar 18 – Apr 8Aug 27 – Sep 10
9bFeb 12Jan 15 – Jan 22Feb 19 – Mar 5Feb 19 – Mar 12Sep 10 – Sep 24
10aJan 26Dec 29 – Jan 5Feb 2 – Feb 16Feb 2 – Feb 23Sep 22 – Oct 6
10bJan 27Dec 30 – Jan 6Feb 3 – Feb 17Feb 3 – Feb 24Sep 20 – Oct 4
11aRareFeb 15 – Apr 15; Aug 1 – Sep 15
11b*RareFeb 15 – Apr 15; Aug 1 – Sep 15
12a*RareFeb 15 – Apr 15; Aug 1 – Sep 15
12bRareFeb 15 – Apr 15; Aug 1 – Sep 15
13a*RareFeb 15 – Apr 15; Aug 1 – Sep 15
13b*RareFeb 15 – Apr 15; Aug 1 – Sep 15

Growing tips

Related guides: which frost date to use · succession and fall planting.

Exact dates for your city

Popular: New York, Los Angeles, Chicago, Houston, Phoenix, Philadelphia, San Antonio, San Diego, Dallas, Jacksonville, Fort Worth, San Jose — or browse all cities by state.

Other crops: Tomato, Pepper, Lettuce, Green Beans, Sweet Corn, Cucumber, Carrot, Onion, Potato, Basil, Spinach, Kale, Broccoli, Peas, Eggplant, Cabbage, Radish, Strawberry, Beets

Zucchini & Summer Squash planting questions

When should I start zucchini & summer squash seeds indoors?

About 3–4 weeks before your last spring frost. Using the median frost dates of cities on this site: zone 5a (median last frost May 4): Apr 6 – Apr 13; zone 6b (median last frost Apr 26): Mar 29 – Apr 5; zone 8a (median last frost Apr 1): Mar 4 – Mar 11.

When can I plant zucchini & summer squash outside?

Set out transplants from 1 week after to 3 weeks after the last frost, once the soil reaches about 65°F (18.3°C). Examples: zone 5a (median last frost May 4): May 11 – May 25; zone 6b (median last frost Apr 26): May 3 – May 17; zone 8a (median last frost Apr 1): Apr 8 – Apr 22.

Can I grow zucchini & summer squash as a fall crop?

Yes. Sow or plant 10–12 weeks before your first fall frost. For a first frost around Oct 15, that is Jul 23 – Aug 6. Add about two weeks to the days to maturity for slower fall growth — see fall planting.

Is my growing season long enough for zucchini & summer squash?

Zucchini & summer squash needs 45–60 days from sowing, and must finish before fall frost. Counting from planting 1 week after the last frost plus two weeks of harvest, slower varieties need about 81 days between the 30% frost dates. That is longer than the season in 0 of the 460 cities on this site with frost dates.

When do you plant zucchini & summer squash where frost is rare?

In frost-free climates, plant zucchini & summer squash Feb 15 – Apr 15 and Aug 1 – Sep 15, timing growth for the mildest months. This applies to cities such as Los Angeles, CA, San Diego, CA, San Francisco, CA.