City	Sow outdoors	Last frost
Salt Lake City	Apr 7 to Apr 21	Mar 31
West Valley City	Apr 15 to Apr 29	Apr 8
West Jordan	Apr 25 to May 9	Apr 18
Provo	Apr 25 to May 9	Apr 18
St. George	Mar 21 to Apr 4	Mar 14
Lehi	May 7 to May 21	Apr 30
Orem	Apr 26 to May 10	Apr 19
Sandy	May 6 to May 20	Apr 29
Ogden	Apr 28 to May 12	Apr 21
South Jordan	Apr 25 to May 9	Apr 18
Layton	May 6 to May 20	Apr 29
Eagle Mountain	Jun 9 to Jun 23	Jun 2
Millcreek	May 2 to May 16	Apr 25
Herriman	Apr 25 to May 9	Apr 18
Saratoga Springs	May 7 to May 21	Apr 30
Taylorsville	Apr 7 to Apr 21	Mar 31
Logan	May 15 to May 29	May 8
Murray	May 6 to May 20	Apr 29
Draper	Apr 25 to May 9	Apr 18
Spanish Fork	May 2 to May 16	Apr 25
Riverton	Apr 25 to May 9	Apr 18
Bountiful	May 2 to May 16	Apr 25
Tooele	May 9 to May 23	May 2
Cedar City	May 11 to May 25	May 4
American Fork	Apr 24 to May 8	Apr 17
Syracuse	Apr 29 to May 13	Apr 22
Roy	Apr 29 to May 13	Apr 22
Pleasant Grove	Apr 24 to May 8	Apr 17
Washington	Mar 21 to Apr 4	Mar 14
Midvale	May 6 to May 20	Apr 29
Springville	Apr 25 to May 9	Apr 18
Kearns	Apr 15 to Apr 29	Apr 8
Magna	Apr 10 to Apr 24	Apr 3
Clearfield	May 6 to May 20	Apr 29
Kaysville	Apr 26 to May 10	Apr 19
Cottonwood Heights	May 6 to May 20	Apr 29
Holladay	May 6 to May 20	Apr 29
South Salt Lake	Apr 7 to Apr 21	Mar 31
Farmington	Apr 26 to May 10	Apr 19
Hurricane	Apr 8 to Apr 22	Apr 1
West Haven	Apr 29 to May 13	Apr 22
Payson	May 11 to May 25	May 4
Clinton	Apr 29 to May 13	Apr 22
North Salt Lake	May 1 to May 15	Apr 24
North Ogden	Apr 26 to May 10	Apr 19
Highland	May 10 to May 24	May 3
Brigham City	May 12 to May 26	May 5

Questions

When should I plant zucchini in Utah?

In Salt Lake City, sow outdoors from April 7 to April 21. Across Utah the window opens between March 21 and June 9, depending on the local last frost.

How is this date worked out?

Sow outdoors 1–3 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.