When to plant Potatoes in District of Columbia

In spring, Feb 20 – Mar 20 in Washington.

In fall, July 25 – Aug 20 in Washington.

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

Potatoes planting dates by place in District of Columbia
PlaceSpringFall
WashingtonFeb 20 – Mar 20July 25 – Aug 20

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 potatoes.