What is the coldest zone on the USDA plant hardiness map?
What is the coldest zone on the USDA plant hardiness map? Cold Hardiness zones are based on the average annual minimum temperature in a given area of the country, with USDA Zone 1 being the coldest at minus 50 degrees F and USDA Zone 11 the warmest at above 40 degrees F. USDA Plant Hardiness […]