When to plant swiss chard in Delaware
Delaware’s average last spring frost is April 14, and the first fall frost typically arrives around October 22 — about 191 frost-free days (USDA zones 7a, 7b). Swiss Chard needs 50–60 days to mature, which fits comfortably within Delaware's growing season.
When to plant swiss chard in Delaware: the short answer
For a spring planting, plant out Mar 24 – Apr 10, with seeds started indoors Mar 10 – Mar 24. 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 Delaware, step by step
- Start seeds indoors (Mar 10 – Mar 24). 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 (Mar 24 – Apr 10). 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 Delaware.
- 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 May 20 – May 30). 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 Delaware’s average frost dates. More in the full swiss chard growing guide.
When to plant swiss chard in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Delaware (this page) | April 14 | Mar 24 – Apr 10 |
| New Jersey | April 20 | Mar 30 – Apr 16 |
| Pennsylvania | May 1 | Apr 10 – Apr 27 |
| Maryland | April 14 | Mar 24 – Apr 10 |
| District of Columbia | April 10 | Mar 20 – Apr 6 |
| Virginia | April 15 | Mar 25 – Apr 11 |
| West Virginia | May 5 | Apr 14 – May 1 |
Questions gardeners in Delaware ask
When is the best time to plant swiss chard in Delaware?
Plant swiss chard transplants outdoors in Delaware between March 24 and April 10. That timing is set by Delaware's average last spring frost of April 14.
When should I start swiss chard seeds indoors in Delaware?
Start seeds indoors between March 10 and March 24, about 4 weeks before the last frost, so the seedlings are ready to plant out from March 24.
Can I plant swiss chard in the fall in Delaware?
Yes. For a fall crop, sow between August 3 and August 20, so the crop matures in cool weather before Delaware's first frost around October 22.
When will swiss chard planted in Delaware be ready to harvest?
Planted on time, swiss chard is usually ready from about May 20 to May 30, 50-60 days after planting.
When is the last frost in Delaware?
On average around April 14, with the first fall frost around October 22 - about 191 frost-free days. Your town may differ by two weeks or more.