What plant hardiness zone is Great Mills
Great Mills is located at St. Mary's County, Maryland (MD), USA.
Plant hardiness zone (winter frost zone or gardening zone) for Great Mills is 7b by the USDA scale.
Coldest zone's winter temperature is +5 … +10 °F.
Plants of 7b USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 7b USDA.
Great Mills, Maryland @ wikipedia.