Plant Spinach in Zone 3a

Zone 3a averages 123 frost-free days, running from a last spring frost around May 15 to a first fall frost around September 15. Spinach needs roughly 45 days from planting out to first harvest, so it uses about 37 percent of that window. Spinach is a hardy crop, which is what decides where in the window it belongs.

Spinach handles cold soil, so there is no reason to wait for the frost date. Direct sow around Apr 10, roughly 5 weeks before the Zone 3a last frost, as soon as the ground is workable. Sowing at the last frost instead costs you the coolest and best part of the season. At 45 days to harvest, a 123-day Zone 3a season has room for about 2 sowings, so stagger them rather than planting everything at once.

Yes. Plant spinach between August 4 and August 18 in Zone 3a, roughly 6 to 4 weeks before the average first frost, so it roots before the ground freezes.

Spinach sown 4 to 6 weeks before the first frost sizes up, stalls through winter under a row cover, and restarts weeks before anything can be sown in spring.