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

Questions

When should I plant swiss chard in Utah?

In Salt Lake City, sow outdoors from March 17 to April 14. Across Utah the window opens between February 28 and May 19, depending on the local last frost.

How is this date worked out?

Sow outdoors from 2 weeks before to 2 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.