When to plant spinach in Minnesota
Minnesota’s average last spring frost is May 6, and the first fall frost typically arrives around September 28 — about 145 frost-free days (USDA zones 3a, 3b, 4a, 4b, 5a). Spinach needs 37–45 days to mature, which fits comfortably within Minnesota's growing season.
When to plant spinach in Minnesota: the short answer
For a spring planting, sow Mar 27 – Apr 15. Seeds germinate in soil from 35 to 75°F.
Succession sow again in Minnesota: Apr 13 · Apr 25 · May 7 · May 19 · May 31
Spring succession stops before summer heat makes it bolt. Start sowing again in late summer for a fall crop (see the fall window above).
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow spinach in Minnesota, step by step
- Prepare the bed. It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough and loose soil at least 12 inches deep, with a pH between 6.0 and 7.5. Dig in compost before planting.
- Sow outdoors (Mar 27 – Apr 15). Space plants about 4 inches apart in rows 12 inches apart, sowing seed ½ inch deep. It tolerates hard frost, so it is one of the first crops to plant. As a cool-season crop it does best before summer heat arrives in Minnesota.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: leaf miner, aphids, flea beetle. Diseases and disorders: downy mildew, white rust, damping off.
- Harvest (from about May 8 – May 16). Spinach takes 37-45 days to reach harvest. Bolts fast in heat and long days - it is really a spring and fall crop. A late-fall sowing under row cover often overwinters for an early-spring cut.
Figures come from our crop data; dates use Minnesota’s average frost dates. More in the full spinach growing guide.
Spinach planting dates by USDA zone in Minnesota
Minnesota spans USDA zones 3a, 3b, 4a, 4b, 5a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the spinach dates shift with them.
When to plant spinach in nearby states
Questions gardeners in Minnesota ask
When is the best time to plant spinach in Minnesota?
Sow spinach in Minnesota between March 27 and April 15. That timing is set by Minnesota's average last spring frost of May 6.
Can I plant spinach in the fall in Minnesota?
Yes. For a fall crop, sow between July 31 and August 17, so the crop matures in cool weather before Minnesota's first frost around September 28.
When will spinach planted in Minnesota be ready to harvest?
Planted on time, spinach is usually ready from about May 8 to May 16, 37-45 days after sowing.
When is the last frost in Minnesota?
On average around May 6, with the first fall frost around September 28 - about 145 frost-free days. Your town may differ by two weeks or more.