When to plant kale 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). Kale needs 50–65 days to mature, which fits comfortably within Delaware's growing season.
When to plant kale in Delaware: the short answer
For a spring planting, plant out Mar 17 – Apr 3, with seeds started indoors Feb 24 – Mar 10. Seeds germinate in soil from 45 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 kale in Delaware, step by step
- Start seeds indoors (Feb 24 – Mar 10). Sow seeds ½ inch deep in seed-starting mix under bright light. They take 5-10 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 18 inches deep, with a pH between 6.0 and 7.5. Dig in compost before planting.
- Plant out (Mar 17 – Apr 3). Space plants about 16 inches apart in rows 20 inches apart. 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 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: cabbage worm, cabbage looper, cabbage aphid, flea beetle, harlequin bug. Diseases and disorders: black rot, clubroot, downy mildew.
- Harvest (from about May 13 – May 28). Kale takes 50-65 days to reach harvest. Flavour turns sweet after a hard frost, so the fall crop is the good one. Pick lower leaves and let the plant keep growing upward.
Figures come from our crop data; dates use Delaware’s average frost dates. More in the full kale growing guide.
When to plant kale in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Delaware (this page) | April 14 | Mar 17 – Apr 3 |
| New Jersey | April 20 | Mar 23 – Apr 9 |
| Pennsylvania | May 1 | Apr 3 – Apr 20 |
| Maryland | April 14 | Mar 17 – Apr 3 |
| District of Columbia | April 10 | Mar 13 – Mar 30 |
| Virginia | April 15 | Mar 18 – Apr 4 |
| West Virginia | May 5 | Apr 7 – Apr 24 |
Questions gardeners in Delaware ask
When is the best time to plant kale in Delaware?
Plant kale transplants outdoors in Delaware between March 17 and April 3. That timing is set by Delaware's average last spring frost of April 14.
When should I start kale seeds indoors in Delaware?
Start seeds indoors between February 24 and March 10, about 6 weeks before the last frost, so the seedlings are ready to plant out from March 17.
Can I plant kale in the fall in Delaware?
Yes. For a fall crop, sow between July 27 and August 13, so the crop matures in cool weather before Delaware's first frost around October 22.
When will kale planted in Delaware be ready to harvest?
Planted on time, kale is usually ready from about May 13 to May 28, 50-65 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.