When to plant Radishes in District of Columbia

In spring, Feb 15 – May 1 in Washington.

In fall, Sept 1 – Nov 15 in Washington.

USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.

Radishes planting dates by place in District of Columbia
PlaceSpringFall
WashingtonFeb 15 – May 1Sept 1 – Nov 15Now

Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. “—” means the place's frost date is outside the table. The full USDA table for radishes.