When to plant cauliflower 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). Cauliflower needs 60–90 days to mature, which fits comfortably within Delaware's growing season.
When to plant cauliflower in Delaware: the short answer
For a spring planting, plant out Mar 24 – Apr 10, 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 cauliflower 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 75°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day 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 24 – Apr 10). Space plants about 18 inches apart in rows 30 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. It needs plenty of water; keep the soil evenly moist and never let it dry out.
- Watch for pests and problems. Pests: cabbage worm, cabbage looper, aphids, cabbage root maggot. Diseases and disorders: clubroot, black rot, downy mildew.
- Harvest (from about May 30 – Jun 29). Cauliflower takes 60-90 days to reach harvest. The fussiest brassica - any check from cold, heat, or drought ruins the head. Fall crops are far more reliable than spring. Blanch white types by tying leaves over the curd.
Figures come from our crop data; dates use Delaware’s average frost dates. More in the full cauliflower growing guide.
When to plant cauliflower 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 cauliflower in Delaware?
Plant cauliflower 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 cauliflower 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 24.
Can I plant cauliflower in the fall in Delaware?
Yes. For a fall crop, start transplants between July 13 and July 30, so the crop matures in cool weather before Delaware's first frost around October 22.
When will cauliflower planted in Delaware be ready to harvest?
Planted on time, cauliflower is usually ready from about May 30 to June 29, 60-90 days after transplanting.
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.