When to plant swiss chard 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). Swiss Chard needs 50–60 days to mature, which fits comfortably within New Hampshire's growing season.
When to plant swiss chard in New Hampshire: the short answer
For a spring planting, plant out Apr 22 – May 9, with seeds started indoors Apr 8 – Apr 22. Seeds germinate in soil from 40 to 85°F.
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 swiss chard in New Hampshire, step by step
- Start seeds indoors (Apr 8 – Apr 22). Sow seeds 0.75 inch deep in seed-starting mix under bright light. They take 5-14 days to sprout, fastest in soil around 70°F. Harden seedlings off for a week before they go outside.
- 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.
- Plant out (Apr 22 – May 9). Space plants about 9 inches apart in rows 18 inches apart. It tolerates a light frost but not a hard freeze. 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: cercospora leaf spot, downy mildew.
- Harvest (from about Jun 18 – Jun 28). Swiss Chard takes 50-60 days to reach harvest. One of the most heat-tolerant leafy greens - a single spring sowing usually carries through summer into fall if kept picked.
Figures come from our crop data; dates use New Hampshire’s average frost dates. More in the full swiss chard growing guide.
Swiss Chard 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 swiss chard dates shift with them.
When to plant swiss chard in nearby states
| State | Last frost | Plant out |
|---|---|---|
| New Hampshire (this page) | May 13 | Apr 22 – May 9 |
| Maine | May 14 | Apr 23 – May 10 |
| Vermont | May 14 | Apr 23 – May 10 |
| Massachusetts | April 24 | Apr 3 – Apr 20 |
| Rhode Island | April 25 | Apr 4 – Apr 21 |
| Connecticut | April 25 | Apr 4 – Apr 21 |
| New York | May 1 | Apr 10 – Apr 27 |
Questions gardeners in New Hampshire ask
When is the best time to plant swiss chard in New Hampshire?
Plant swiss chard transplants outdoors in New Hampshire between April 22 and May 9. That timing is set by New Hampshire's average last spring frost of May 13.
When should I start swiss chard seeds indoors in New Hampshire?
Start seeds indoors between April 8 and April 22, about 4 weeks before the last frost, so the seedlings are ready to plant out from April 22.
Can I plant swiss chard in the fall in New Hampshire?
Yes. For a fall crop, sow between July 7 and July 24, so the crop matures in cool weather before New Hampshire's first frost around September 25.
When will swiss chard planted in New Hampshire be ready to harvest?
Planted on time, swiss chard is usually ready from about June 18 to June 28, 50-60 days after planting.
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.