Merriam Woods, Missouri is in USDA Hardiness Zones 6b
Merriam Woods, Missouri Hardiness Zone Map
Merriam Woods Border
Zone 6b -5°F to 0°F
A hardiness zone is a geographically defined area in which a specific category of plant life is capable of growing, as defined by climatic conditions, including its ability to withstand the minimum temperatures of the zone.