When to plant Cucumbers in District of Columbia

In spring, Apr 10 – May 15 in Washington.

In fall, June 1 – Aug 15 in Washington.

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

Cucumbers planting dates by place in District of Columbia
PlaceSpringFall
WashingtonApr 10 – May 15June 1 – Aug 15

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 cucumbers.