Zone 3b planting calendar
What to plant in September — zone 3b
Zone 3b averages its last spring frost around May 25 and its first fall frost around September 15. 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 25
First frost: September 15
Winter lows: -35 to -30 °F
Plant to overwinter
- Garlicaround Sep 1
Cloves go in about two weeks before first frost — they root now, sleep, then bulb next summer.
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