When to plant radishes in Kansas
Kansas’s average last spring frost is April 15, and the first fall frost typically arrives around October 20 — about 188 frost-free days (USDA zones 5b, 6a, 6b, 7a). Radish needs 22–30 days to mature, which fits comfortably within Kansas's growing season.
When to plant radishes in Kansas: the short answer
For a spring planting, sow Mar 13 – Apr 1. Seeds germinate in soil from 40 to 85°F.
Succession sow again in Kansas: Mar 28 · Apr 7 · Apr 17 · Apr 27 · May 7 · May 17
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 Kansas, 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 (Mar 13 – Apr 1). 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 Kansas.
- 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 Apr 9 – Apr 17). 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 Kansas’s average frost dates. More in the full radish growing guide.
Radish planting dates by USDA zone in Kansas
Kansas spans USDA zones 5b, 6a, 6b, 7a. 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 |
|---|---|---|
| Kansas (this page) | April 15 | Mar 13 – Apr 1 |
| North Dakota | May 15 | Apr 12 – May 1 |
| South Dakota | May 10 | Apr 7 – Apr 26 |
| Nebraska | April 30 | Mar 28 – Apr 16 |
| Oklahoma | April 1 | Feb 27 – Mar 18 |
Questions gardeners in Kansas ask
When is the best time to plant radishes in Kansas?
Sow radishes in Kansas between March 13 and April 1. That timing is set by Kansas's average last spring frost of April 15.
Can I plant radishes in the fall in Kansas?
Yes. For a fall crop, sow between September 5 and September 22, so the crop matures in cool weather before Kansas's first frost around October 20.
When will radishes planted in Kansas be ready to harvest?
Planted on time, radishes are usually ready from about April 9 to April 17, 22-30 days after sowing.
When is the last frost in Kansas?
On average around April 15, with the first fall frost around October 20 - about 188 frost-free days. Your town may differ by two weeks or more.