"The map reflects what the plants have known for years."
January 25, 2012 9:00 PM Subscribe
The USDA has released an updated version of its plant hardiness zone map. Based on low temperatures from 1976 to 2005, it puts most US locations into a slightly warmer planting zone. While many headlines link the overall changes with global warming, the map also reflects factors such as urban heat, prevailing winds, and the slope of the land. The Washington Post has an interactive graphic showing the old and new zones.
This thread has been archived and is closed to new comments