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When to plant lettuce in zone 4b

In zone 4b, where the last spring frost typically comes around May 8, start lettuce indoors March 13 to 27 and plant out May 1 to 15. For a fall crop, plant July 2 to August 6.

The zone 4b schedule for lettuce

Start seeds indoors
March 13 to 27
Plant out
May 1 to 15
Sow outdoors
April 17 to 24
First harvest, roughly
May 31 to July 24
Plant for a fall crop
July 2 to August 6

From the median frost dates of the NOAA stations assigned to the 1,164 ZIP codes in zone 4b, and the timing recommended by Cooperative Extension guides for lettuce.

Dates before the last frost assume the soil has thawed and is dry enough to work: a squeezed handful crumbles instead of sticking. After a late or wet spring, wait for that even if the date has passed.

Frost risk in zone 4b

Zones are based on winter cold, not on frost dates, so the last spring frost varies a lot within a zone. Across zone 4b, the typical last frost ranges from about May 1 in the earliest tenth of ZIP codes to May 25 in the latest tenth, and the first fall frost from September 22 to October 8. For a typical place in the zone:

  • April 26Risky: a later frost happens in 9 years out of 10
  • May 8Typical: frost after this date in half of years
  • May 22Safe: a later frost only 1 year in 10

Your dates for lettuce

Set your ZIP code at the top of the page and we will work out when to plant lettuce where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.

Enter your ZIP code

Lettuce in zone 4b cities

CityTypical last frostStart indoorsPlant out
Rochester, MNApr 30Mar 5 to 19Apr 23 to May 7
Duluth, MNMay 6Mar 11 to 25Apr 29 to May 13
Lakeville, MNMay 2Mar 7 to 21Apr 25 to May 9
St. Cloud, MNMay 7Mar 12 to 26Apr 30 to May 14
Eau Claire, WIMay 8Mar 13 to 27May 1 to 15
Great Falls, MTMay 19Mar 24 to Apr 7May 12 to 26

How to grow lettuceAll zonesLettuce in zone 4aLettuce in zone 5aAbout zone 4b

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