This map will enable professionals to identify plants that won't succumb to heat damage. The Heat Zone Map divides the country into 12 zones, based on the number of days each year that the daily high temperatures reach or exceed 86 degrees, the temperature at which plants begin to sustain physiological damage. The data used to create the map was gathered from nearly 5,000 weather stations across the country. The two-foot by three-foot map is laminated and is shipped unfolded in a tube.   NOW ON SALE!!! WAS $14.95 -- NOW $9.75! SUPPLIES LIMITED ORDER NOW!