When to plant Onion sets in Maryland

In spring, from Feb 1 – Mar 20 in Baltimore to Mar 10 – Apr 1 in Westminster.

In fall, from Oct 1 – Dec 1 in Annapolis to Nov 1 – Dec 31 in Baltimore.

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

Onion sets planting dates by place in Maryland
PlaceSpringFall
AberdeenMar 1 – Apr 1Not listed
AnnapolisFeb 15 – Mar 20Oct 1 – Dec 1Now
BaltimoreFeb 1 – Mar 20Nov 1 – Dec 31Soon
Bel AirMar 1 – Apr 1Not listed
BowieMar 10 – Apr 1Spring-planted
CambridgeFeb 15 – Mar 20Oct 1 – Dec 1Now
College ParkMar 1 – Apr 1Not listed
CumberlandMar 1 – Apr 1Spring-planted
EastonFeb 15 – Mar 20Oct 1 – Dec 1Now
ElktonMar 1 – Apr 1Not listed
FrederickFeb 15 – Mar 20Oct 1 – Dec 1Now
GaithersburgFeb 15 – Mar 20Oct 1 – Dec 1Now
GreenbeltMar 1 – Apr 1Not listed
HagerstownMar 1 – Apr 1Not listed
Havre de GraceMar 1 – Apr 1Not listed
HyattsvilleFeb 15 – Mar 20Oct 1 – Dec 1Now
La PlataMar 10 – Apr 1Not listed
LaurelMar 1 – Apr 1Oct 1 – Dec 1Now
New CarrolltonMar 10 – Apr 1Spring-planted
RockvilleFeb 15 – Mar 20Oct 1 – Dec 1Now
SalisburyFeb 15 – Mar 20Oct 1 – Dec 1Now
Takoma ParkFeb 15 – Mar 20Oct 1 – Dec 1Now
WestminsterMar 10 – Apr 1Spring-planted

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 onion sets.