Take a backroads trip up Mount Lemmon Scenic Byway near Tucson, Arizona. Our drive up one of the most scenic drives in southeast Arizona made for a perfect day. After several days in Tucson in over 100 degree heat in May, we really needed a break.      MOUNT LEMMON     Mount Lemmon has a summit elevation of 9,156 feet and is the highest point in the Santa Catalina Mountains, located in the Coronado National Forest north of Tucson. The 27-mile Byway is the biological equivalent of driving from the deserts of Mexico to the forests of Canada! Just imagine! As gardeners, Stu and I were fascinated by the changes in plant life!    …