When to plant cauliflower in Oklahoma
Oklahoma’s average last spring frost is April 1, and the first fall frost typically arrives around November 1 — about 214 frost-free days (USDA zones 6b, 7a, 7b, 8a). Cauliflower needs 60–90 days to mature, which fits comfortably within Oklahoma's growing season.
When to plant cauliflower in Oklahoma: the short answer
For a spring planting, plant out Mar 11 – Mar 28, with seeds started indoors Feb 11 – Feb 25. 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 Oklahoma, step by step
- Start seeds indoors (Feb 11 – Feb 25). 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 11 – Mar 28). 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 Oklahoma.
- 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 17 – Jun 16). 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 Oklahoma’s average frost dates. More in the full cauliflower growing guide.
Cauliflower planting dates by USDA zone in Oklahoma
Oklahoma spans USDA zones 6b, 7a, 7b, 8a. 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 cauliflower dates shift with them.
When to plant cauliflower in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Oklahoma (this page) | April 1 | Mar 11 – Mar 28 |
| North Dakota | May 15 | Apr 24 – May 11 |
| South Dakota | May 10 | Apr 19 – May 6 |
| Nebraska | April 30 | Apr 9 – Apr 26 |
| Kansas | April 15 | Mar 25 – Apr 11 |
Questions gardeners in Oklahoma ask
When is the best time to plant cauliflower in Oklahoma?
Plant cauliflower transplants outdoors in Oklahoma between March 11 and March 28. That timing is set by Oklahoma's average last spring frost of April 1.
When should I start cauliflower seeds indoors in Oklahoma?
Start seeds indoors between February 11 and February 25, about 6 weeks before the last frost, so the seedlings are ready to plant out from March 11.
Can I plant cauliflower in the fall in Oklahoma?
Yes. For a fall crop, start transplants between July 23 and August 9, so the crop matures in cool weather before Oklahoma's first frost around November 1.
When will cauliflower planted in Oklahoma be ready to harvest?
Planted on time, cauliflower is usually ready from about May 17 to June 16, 60-90 days after transplanting.
When is the last frost in Oklahoma?
On average around April 1, with the first fall frost around November 1 - about 214 frost-free days. Your town may differ by two weeks or more.