2012 brings a new and revised Plant Hardiness Zone Map which was recently published by the USDA.  This map has 30 years of weather data in it’s making (1976-2005).  The previous edition was published in 1990. The hardiness zones are created from the average annual extreme minimum temperatures from the past.  Here are a few highlights about the map: This is the first PHZM specifically … Continue reading New USDA Plant Hardiness Zone Map