When to plant kale 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). Kale needs 50–65 days to mature, which fits comfortably within Oklahoma's growing season.
When to plant kale in Oklahoma: the short answer
For a spring planting, plant out Mar 4 – Mar 21, 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 kale 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 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 4 – Mar 21). 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 Oklahoma.
- 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 Apr 30 – May 15). 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 Oklahoma’s average frost dates. More in the full kale growing guide.
Kale 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 kale dates shift with them.
When to plant kale in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Oklahoma (this page) | April 1 | Mar 4 – Mar 21 |
| North Dakota | May 15 | Apr 17 – May 4 |
| South Dakota | May 10 | Apr 12 – Apr 29 |
| Nebraska | April 30 | Apr 2 – Apr 19 |
| Kansas | April 15 | Mar 18 – Apr 4 |
Questions gardeners in Oklahoma ask
When is the best time to plant kale in Oklahoma?
Plant kale transplants outdoors in Oklahoma between March 4 and March 21. That timing is set by Oklahoma's average last spring frost of April 1.
When should I start kale 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 4.
Can I plant kale in the fall in Oklahoma?
Yes. For a fall crop, sow between August 6 and August 23, so the crop matures in cool weather before Oklahoma's first frost around November 1.
When will kale planted in Oklahoma be ready to harvest?
Planted on time, kale is usually ready from about April 30 to May 15, 50-65 days after planting.
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.