Plant Hardiness Zones: Know Where You Grow!
The first official hardiness zone map was released by theUnited States Department of Agriculture(USDA ) in 1960 . It has been adapted to varying degrees by other countries , let in Canada and Mexico . Hardiness zones vary from 0 to 13 . The orbit tells us what the average winter extreme point low is . This relates to plant survival of the fittest and the possible edible diversity for a belongings or farm ....