In zone 6, sow spinach from March 20 to April 10, three to six weeks before your last spring frost, once the soil reaches about 45 °F. It is ready in about 40 days. For a fall crop, the last sowing date is about August 18.
Spinach dates for your ZIP code
Planting times based on university extension guidance (UNH, Cornell, Purdue, Minnesota, Nebraska and UMass Extension). Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Spinach timing in zone 6
| Task | When |
|---|---|
| Sow outside | March 20 – April 10 |
| First harvest | April 27 – May 25 |
| Sow for fall by | August 18 |
| Sow again | Every 2 weeks in spring and late summer |
| Thin | When leaves touch and plants are about 2 inches tall |
| Fall harvest | Into December with protection |
Most of zone 6 sees its last spring frost between April 25 and May 8 (typical May 1) and its first fall frost between October 7 and October 18 (typical October 13). Spinach tolerates frost, so early sowing is safe. The tool above uses the weather station closest to your ZIP code.
Why spinach is planted early
Spinach is a cool-season crop that grows best at 50–60 °F and tolerates frost. It bolts, sending up a flower stalk and turning bitter, as the days lengthen and warm up in late spring. That is why it is sown weeks before the last spring frost, and again in late summer for fall.
Best spinach varieties for zone 6
In zone 6, spinach has two seasons, spring and fall. Choose by season:
- Slow-bolting, for spring: Tyee, Olympia, Space, Acadia and Indian Summer.
- Hardy, for fall and overwintering: Bloomsdale Long Standing.
- Savoy or smooth leaves: savoy types have crinkled leaves; smooth types are easier to wash.
How to plant spinach
- Sow seeds directly in the garden, about ½ inch deep, once the soil is about 45 °F.
- Space seeds 1–4 inches apart in rows or wide beds.
- Thin when the leaves touch and plants are about 2 inches tall. Eat the thinnings.
- Sow again every two weeks for a continuous harvest.
- Keep the soil evenly moist for fast, tender growth.
Zone 6 spinach tips
- Plant early in spring. Spinach bolts as the days lengthen and warm up, so the earlier it goes in, the longer you harvest.
- Grow your best crop in fall. Spinach handles frost and can be harvested into December with a row cover or cold frame.
- Overwinter for an early spring crop. In mild areas, late-fall sowings survive winter and start growing again in spring.
- Try heat-loving substitutes for summer: New Zealand spinach and Malabar spinach grow well in hot weather.
Harvesting spinach
Spinach is ready in about 27–50 days, depending on the variety. Cut the full-size outer leaves and leave the center to keep growing, or cut the whole plant. Once it starts to send up a flower stalk, harvest everything, because the leaves turn bitter.
Spinach planting dates in nearby zones
See dates for every zone on the spinach planting guide, or build a full schedule with the planting calendar.
Frequently asked questions
Is it too late to plant spinach in zone 6 in April?
For spring, yes: spinach sown in April bolts in the long, warm days. Sow again in late summer, by about August 18, for a fall crop.
Can I grow spinach in summer in zone 6?
Not true spinach, which bolts in heat. Grow New Zealand spinach or Malabar spinach instead, which thrive in hot weather.
Can spinach handle frost?
Yes. Spinach is frost tolerant and grows best in cool weather, so it is sown three to six weeks before your last spring frost.
Why does my spinach bolt?
Long days and warm temperatures in late spring trigger bolting. Sow early and choose slow-bolting varieties such as Tyee or Olympia.
How deep should spinach seeds be planted?
About ½ inch deep, 1–4 inches apart.
Sources. Planting dates use the median frost dates of each USDA zone, calculated from NOAA climate data for every ZIP code in the zone.