When to plant radishes in Michigan
Michigan’s average last spring frost is May 10, and the first fall frost typically arrives around October 5 — about 148 frost-free days (USDA zones 4a, 4b, 5a, 5b, 6a, 6b). Radish needs 22–30 days to mature, which fits comfortably within Michigan's growing season.
Michigan covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant radishes in Michigan: the short answer
For a spring planting, sow Apr 7 – Apr 26. Seeds germinate in soil from 40 to 85°F.
Succession sow again in Michigan: Apr 22 · May 2 · May 12 · May 22 · Jun 1 · Jun 11
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 Michigan, 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 (Apr 7 – Apr 26). 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 Michigan.
- 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 May 4 – May 12). 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 Michigan’s average frost dates. More in the full radish growing guide.
Radish planting dates by USDA zone in Michigan
Michigan spans USDA zones 4a, 4b, 5a, 5b, 6a, 6b. 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
Questions gardeners in Michigan ask
When is the best time to plant radishes in Michigan?
Sow radishes in Michigan between April 7 and April 26. That timing is set by Michigan's average last spring frost of May 10; Michigan spans several climates, so cooler and higher parts of the state run later.
Can I plant radishes in the fall in Michigan?
Yes. For a fall crop, sow between August 21 and September 7, so the crop matures in cool weather before Michigan's first frost around October 5.
When will radishes planted in Michigan be ready to harvest?
Planted on time, radishes are usually ready from about May 4 to May 12, 22-30 days after sowing.
When is the last frost in Michigan?
On average around May 10, with the first fall frost around October 5 - about 148 frost-free days. Your town may differ by two weeks or more.