When to plant radishes
Radishes are a cool-season crop that tolerates light frost and prefers to grow in cool weather. Ready in about a month — sow a few every week in spring and fall.
- Sow seeds outdoors 5 weeks before to 1 week after the last spring frost.
- For a fall crop, sow 3–6 weeks before the first fall frost.
About 25 days from planting to harvest.
Get exact dates for your garden
Planting dates by hardiness zone
| Zone | Typical last frost | Start indoors | Sow outdoors | Fall crop |
|---|---|---|---|---|
| 2a | May 24 | — | Apr 19 – May 31 | Jul 26 – Aug 16 |
| 3b | May 17 | — | Apr 12 – May 24 | Aug 13 – Sep 3 |
| 4a | May 12 | — | Apr 7 – May 19 | Aug 17 – Sep 7 |
| 4b | May 8 | — | Apr 3 – May 15 | Aug 20 – Sep 10 |
| 5a | May 3 | — | Mar 29 – May 10 | Aug 24 – Sep 14 |
| 5b | May 1 | — | Mar 27 – May 8 | Aug 30 – Sep 20 |
| 6a | Apr 29 | — | Mar 25 – May 6 | Sep 5 – Sep 26 |
| 6b | Apr 22 | — | Mar 18 – Apr 29 | Sep 10 – Oct 1 |
| 7a | Apr 16 | — | Mar 12 – Apr 23 | Sep 13 – Oct 4 |
| 7b | Apr 5 | — | Mar 1 – Apr 12 | Sep 20 – Oct 11 |
| 8a | Mar 29 | — | Feb 22 – Apr 5 | Sep 26 – Oct 17 |
| 8b | Mar 16 | — | Feb 9 – Mar 23 | Oct 3 – Oct 24 |
| 9a | Mar 3 | — | Jan 27 – Mar 10 | Oct 14 – Nov 4 |
| 9b | Feb 20 | — | Jan 16 – Feb 27 | Oct 24 – Nov 14 |
| 10a | Mar 2 | — | Jan 26 – Mar 9 | Oct 20 – Nov 10 |
Zone rows use the median frost dates of all ZIP codes in that zone. Zones measure winter cold, not season length, so two places in the same zone can have frost dates weeks apart — use your ZIP code for real dates.
When to plant radishes in major cities
| City | Median last frost | Sow outdoors | Fall crop |
|---|---|---|---|
| Seattle, WA | Mar 13 | Feb 6 – Mar 20 | Oct 6 – Oct 27 |
| Portland, OR | Feb 25 | Jan 21 – Mar 4 | Oct 20 – Nov 10 |
| Salt Lake City, UT | Apr 25 | Mar 21 – May 2 | Sep 6 – Sep 27 |
| Denver, CO | Apr 30 | Mar 26 – May 7 | Aug 31 – Sep 21 |
| Minneapolis, MN | Apr 23 | Mar 19 – Apr 30 | Sep 4 – Sep 25 |
| Chicago, IL | Apr 10 | Mar 6 – Apr 17 | Sep 24 – Oct 15 |
| Detroit, MI | Apr 27 | Mar 23 – May 4 | Sep 13 – Oct 4 |
| Kansas City, MO | Apr 4 | Feb 28 – Apr 11 | Sep 21 – Oct 12 |
| Columbus, OH | Apr 20 | Mar 16 – Apr 27 | Sep 12 – Oct 3 |
| Boston, MA | Apr 4 | Feb 28 – Apr 11 | Sep 28 – Oct 19 |
| New York, NY | Mar 30 | Feb 23 – Apr 6 | Oct 9 – Oct 30 |
| Philadelphia, PA | Mar 30 | Feb 23 – Apr 6 | Oct 6 – Oct 27 |
| Washington, DC | Mar 29 | Feb 22 – Apr 5 | Sep 27 – Oct 18 |
| Charlotte, NC | Mar 30 | Feb 23 – Apr 6 | Sep 22 – Oct 13 |
| Nashville, TN | Apr 1 | Feb 25 – Apr 8 | Sep 19 – Oct 10 |
| Atlanta, GA | Mar 25 | Feb 18 – Apr 1 | Sep 28 – Oct 19 |
| Dallas, TX | Mar 2 | Jan 26 – Mar 9 | Oct 18 – Nov 8 |
Growing radishes: quick facts
| Frost tolerance | Hardy: survives hard frosts, down to about 25°F or colder |
|---|---|
| Soil temperature | at least 40°F to germinate; 45–90°F is ideal |
| Planting depth | ½ in |
| Spacing | 1–2 in |
| Germination | 3–7 days |
| Days to harvest | about 25 days from planting |
Typical figures from university extension planting guides. Seed packets give the best numbers for a specific variety.