Zone 3a planting calendar
What to plant in September — zone 3a
Zone 3a averages its last spring frost around May 30 and its first fall frost around September 10. Everything below is timed from those two dates, so it stays useful whether you're planting for summer or for a fall harvest.
Last frost: May 30
First frost: September 10
Winter lows: -40 to -35 °F
A quiet month in zone 3a
September is a rest-and-plan month here. Use it to order seed, test your soil, repair beds, and map next season's rotation — then jump ahead to October.
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