Radishes are sown two to four weeks before your last spring frost, in short rows every 10–14 days, and again in late summer for fall. Find your zone below, or enter your ZIP code for dates based on the weather station closest to you.
Radish dates for your ZIP code
Planting times based on university extension guidance (UNH, Cornell, Purdue, Minnesota, Nebraska and UMass Extension). Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Radish planting dates by zone
| USDA zone | When to plant |
|---|---|
| Zone 3 | April 25 – May 9 |
| Zone 4 | April 18 – May 2 |
| Zone 5 | April 10 – April 24 |
| Zone 6 | April 3 – April 17 |
| Zone 7 | March 20 – April 3 |
| Zone 8 | March 3 – March 17 |
| Zone 9 | February 3 – February 17 |
Not sure of your zone? Look it up by ZIP code.
Why radishes are sown early
Radishes are a fast, cool-season crop that tolerates frost. In cool weather they grow quickly and stay crisp and mild. Heat and slow growth make them hot, pithy and quick to send up seed stalks. That is why they are sown two to four weeks before the last spring frost, and again in late summer.
How to plant radishes
- Sow seeds ¼–½ inch deep directly in the garden.
- Thin spring radishes to ½–1 inch apart, and winter radishes to 2–4 inches.
- Sow a short row every 10–14 days for a steady harvest.
- Keep the soil evenly moist so roots grow fast and don’t split.
Harvesting radishes
Pull spring radishes when the roots are under about an inch across, usually 25–30 days after sowing. Check them often, because they turn pithy and hot quickly once mature. Remove the greens before storing; radishes keep 5–7 days in the refrigerator. Winter radishes can stay in the garden into fall and keep for months in cold storage.
Frequently asked questions
How long do radishes take to grow?
Spring radishes are ready in about 25–30 days. Winter radishes such as daikon take longer and grow much larger.
Can radishes handle frost?
Yes. Radishes are frost tolerant and are sown two to four weeks before your last spring frost.
Why are my radishes all leaves and no root?
Usually crowding or heat. Thin seedlings to at least ½–1 inch apart, and sow in cool weather.
Sources. Planting dates use the median frost dates of each USDA zone, calculated from NOAA climate data for every ZIP code in the zone.