When to plant cucumbers 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). Cucumber needs 50–70 days to mature, which fits comfortably within Delaware's growing season.
When to plant cucumbers in Delaware: the short answer
For a spring planting, plant out Apr 21 – May 8, with seeds started indoors Mar 17 – Mar 31. Wait until the soil is at least 60°F and frost is over.
Succession sow again in Delaware: May 19 · Jun 9 · Jun 30 · Jul 21 · Aug 11
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 cucumbers in Delaware, step by step
- Start seeds indoors (Mar 17 – Mar 31). Sow seeds 1 inch deep in seed-starting mix under bright light. They take 3-10 days to sprout, fastest in soil around 85°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. They need at least six to eight hours of direct sun a day and loose soil at least 14 inches deep, with a pH between 5.5 and 7.0. Dig in compost before planting.
- Plant out (Apr 21 – May 8). Space plants about 12 inches apart in rows 48 inches apart. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. It needs plenty of water; keep the soil evenly moist and never let it dry out.
- Watch for pests and problems. Pests: striped cucumber beetle, squash bug, aphids, spider mite. Diseases and disorders: powdery mildew, downy mildew, bacterial wilt, angular leaf spot.
- Harvest (from about Jun 17 – Jul 7). Cucumber takes 50-70 days to reach harvest. Resents root disturbance - if starting indoors use peat/paper pots. Trellising doubles the plants per square foot and cuts disease. A second sowing in midsummer beats early beetle pressure.
Figures come from our crop data; dates use Delaware’s average frost dates. More in the full cucumber growing guide.
When to plant cucumbers in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Delaware (this page) | April 14 | Apr 21 – May 8 |
| New Jersey | April 20 | Apr 27 – May 14 |
| Pennsylvania | May 1 | May 8 – May 25 |
| Maryland | April 14 | Apr 21 – May 8 |
| District of Columbia | April 10 | Apr 17 – May 4 |
| Virginia | April 15 | Apr 22 – May 9 |
| West Virginia | May 5 | May 12 – May 29 |
Questions gardeners in Delaware ask
When is the best time to plant cucumbers in Delaware?
Plant cucumber transplants outdoors in Delaware between April 21 and May 8. That timing is set by Delaware's average last spring frost of April 14.
When should I start cucumber seeds indoors in Delaware?
Start seeds indoors between March 17 and March 31, about 3 weeks before the last frost, so the seedlings are ready to plant out from April 21.
Can I plant cucumbers in the fall in Delaware?
Yes. For a fall crop, sow between July 20 and August 6, so the crop matures in cool weather before Delaware's first frost around October 22.
When will cucumbers planted in Delaware be ready to harvest?
Planted on time, cucumbers are usually ready from about June 17 to July 7, 50-70 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.