What plant hardiness zone is Merrill
Merrill is located at Lincoln County, Wisconsin (WI), USA.
Plant hardiness zone (winter frost zone or gardening zone) for Merrill is 4a by the USDA scale.
Coldest zone's winter temperature is −30 … -25 °F.
Plants of 4a USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 4a USDA.
Merrill, Wisconsin @ wikipedia.