the.com/growingseason
nature's open enrollment, where every frost-free day is a signature on summer's permission slip
length variesfrom 50 days in Alaska to year-round in Florida
frost defines itbookended by last spring and first fall freeze
climate shiftingUS seasons grew two weeks longer since 1900
degree daysfarmers count heat, not calendar dates
midnight sun trickArctic crops sprint under 24-hour summer light