When to plant radishes 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). Radish needs 22–30 days to mature, which fits comfortably within Oklahoma's growing season.
When to plant radishes in Oklahoma: the short answer
For a spring planting, sow Feb 27 – Mar 18. Seeds germinate in soil from 40 to 85°F.
Succession sow again in Oklahoma: Mar 14 · Mar 24 · Apr 3 · Apr 13 · Apr 23 · May 3
Spring succession stops before summer heat makes it bolt. Start sowing again in late summer for a fall crop (see the fall window above).
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 radishes in Oklahoma, step by step
- Prepare the bed. They need 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 6 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Sow outdoors (Feb 27 – Mar 18). Space plants about 2 inches apart in rows 6 inches apart, sowing seed ½ inch deep. It handles frost well, so it can go out before the last frost date. 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: flea beetle, cabbage root maggot, aphids. Diseases and disorders: clubroot, scab, downy mildew.
- Harvest (from about Mar 26 – Apr 3). Radish takes 22-30 days to reach harvest. The classic marker crop and quick filler. Sow a short row every 10 days - a single big sowing all matures at once and then goes pithy and hot.
Figures come from our crop data; dates use Oklahoma’s average frost dates. More in the full radish growing guide.
Radish 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 radish dates shift with them.
When to plant radishes in nearby states
| State | Last frost | Sow |
|---|---|---|
| Oklahoma (this page) | April 1 | Feb 27 – Mar 18 |
| North Dakota | May 15 | Apr 12 – May 1 |
| South Dakota | May 10 | Apr 7 – Apr 26 |
| Nebraska | April 30 | Mar 28 – Apr 16 |
| Kansas | April 15 | Mar 13 – Apr 1 |
Questions gardeners in Oklahoma ask
When is the best time to plant radishes in Oklahoma?
Sow radishes in Oklahoma between February 27 and March 18. That timing is set by Oklahoma's average last spring frost of April 1.
Can I plant radishes in the fall in Oklahoma?
Yes. For a fall crop, sow between September 17 and October 4, so the crop matures in cool weather before Oklahoma's first frost around November 1.
When will radishes planted in Oklahoma be ready to harvest?
Planted on time, radishes are usually ready from about March 26 to April 3, 22-30 days after sowing.
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.