When to plant radishes in Kentucky
Kentucky’s average last spring frost is April 18, and the first fall frost typically arrives around October 20 — about 185 frost-free days (USDA zones 6a, 6b, 7a). Radish needs 22–30 days to mature, which fits comfortably within Kentucky's growing season.
When to plant radishes in Kentucky: the short answer
For a spring planting, sow Mar 16 – Apr 4. Seeds germinate in soil from 40 to 85°F.
Succession sow again in Kentucky: Mar 31 · Apr 10 · Apr 20 · Apr 30 · May 10 · May 20
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 Kentucky, 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 16 – Apr 4). 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 Kentucky.
- 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 12 – Apr 20). 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 Kentucky’s average frost dates. More in the full radish growing guide.
Radish planting dates by USDA zone in Kentucky
Kentucky spans USDA zones 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 |
|---|---|---|
| Kentucky (this page) | April 18 | Mar 16 – Apr 4 |
| North Carolina | April 5 | Mar 3 – Mar 22 |
| South Carolina | March 25 | Feb 20 – Mar 11 |
| Georgia | March 25 | Feb 20 – Mar 11 |
| Tennessee | April 10 | Mar 8 – Mar 27 |
Questions gardeners in Kentucky ask
When is the best time to plant radishes in Kentucky?
Sow radishes in Kentucky between March 16 and April 4. That timing is set by Kentucky's average last spring frost of April 18.
Can I plant radishes in the fall in Kentucky?
Yes. For a fall crop, sow between September 5 and September 22, so the crop matures in cool weather before Kentucky's first frost around October 20.
When will radishes planted in Kentucky be ready to harvest?
Planted on time, radishes are usually ready from about April 12 to April 20, 22-30 days after sowing.
When is the last frost in Kentucky?
On average around April 18, with the first fall frost around October 20 - about 185 frost-free days. Your town may differ by two weeks or more.