When to plant Swiss chard in New Hampshire

In spring, from Apr 15 – June 15 in Dover to Apr 20 – June 15 in Lebanon.

In fall, June 1 – July 5.

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

Swiss chard planting dates by place in New Hampshire
PlaceSpringFall
ClaremontApr 20 – June 15June 1 – July 5
ConcordApr 20 – June 15June 1 – July 5
DoverApr 15 – June 15June 1 – July 20
KeeneApr 20 – June 15June 1 – July 5
LaconiaApr 15 – June 15June 1 – Aug 1
LebanonApr 20 – June 15June 1 – July 20
ManchesterApr 15 – June 15June 1 – July 20
NashuaApr 15 – June 15June 1 – July 20
PortsmouthApr 15 – June 15June 1 – July 20
RochesterApr 15 – June 15June 1 – July 20
SomersworthApr 15 – June 15June 1 – July 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 swiss chard.