Zone 1b planting calendar

What to plant in September: zone 1b

Zone 1b averages its last spring frost around June 15 and its first fall frost around August 15. Everything below is timed from those two dates, so it stays useful whether you're planting for summer or for a fall harvest.

These are zone-average dates. Check an area-level frost estimate from thirty years of nearby weather history and this calendar retimes itself.

Last frost: June 15

First frost: August 15

Winter lows: -55 to -50 °F

Zone 1b Almanac. What growers here actually recorded: sowing weeks, days to first pick, and yields.

A quiet month in zone 1b

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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