Growing cosmos in zone 6b

(Zone 6b = an average winter low of -5°F to 0°F.)

In USDA zone 6b, the typical last spring frost is April 23 and the first fall frost is October 22. Here is when to plant cosmos against those dates.

USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service / Oregon State University PRISM Group. NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020. Planting windows for cosmos from Utah State University Extension. Zone dates are medians; local conditions vary.