When to plant spinach in New Hampshire
New Hampshire’s average last spring frost is May 13, and the first fall frost typically arrives around September 25 — about 135 frost-free days (USDA zones 3b, 4a, 4b, 5a, 5b, 6a). Spinach needs 37–45 days to mature, which fits comfortably within New Hampshire's growing season.
When to plant spinach in New Hampshire: the short answer
For a spring planting, sow Apr 3 – Apr 22. Seeds germinate in soil from 35 to 75°F.
Succession sow again in New Hampshire: Apr 20 · May 2 · May 14 · May 26 · Jun 7
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 New Hampshire, 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 (Apr 3 – Apr 22). 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 New Hampshire.
- 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 15 – May 23). 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 New Hampshire’s average frost dates. More in the full spinach growing guide.
Spinach planting dates by USDA zone in New Hampshire
New Hampshire spans USDA zones 3b, 4a, 4b, 5a, 5b, 6a. 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
| State | Last frost | Sow |
|---|---|---|
| New Hampshire (this page) | May 13 | Apr 3 – Apr 22 |
| Maine | May 14 | Apr 4 – Apr 23 |
| Vermont | May 14 | Apr 4 – Apr 23 |
| Massachusetts | April 24 | Mar 15 – Apr 3 |
| Rhode Island | April 25 | Mar 16 – Apr 4 |
| Connecticut | April 25 | Mar 16 – Apr 4 |
| New York | May 1 | Mar 22 – Apr 10 |
Questions gardeners in New Hampshire ask
When is the best time to plant spinach in New Hampshire?
Sow spinach in New Hampshire between April 3 and April 22. That timing is set by New Hampshire's average last spring frost of May 13.
Can I plant spinach in the fall in New Hampshire?
Yes. For a fall crop, sow between July 28 and August 14, so the crop matures in cool weather before New Hampshire's first frost around September 25.
When will spinach planted in New Hampshire be ready to harvest?
Planted on time, spinach is usually ready from about May 15 to May 23, 37-45 days after sowing.
When is the last frost in New Hampshire?
On average around May 13, with the first fall frost around September 25 - about 135 frost-free days. Your town may differ by two weeks or more.