I drove through the Great Smoky Mountains around mid-May. I started the uphill climb in Cherokee, North Carolina, which (at around 2000 feet above sea level) has been shed of icy mornings for about a month and a half. I drove through a canopy of mature, deep green. By the time I reached Newfound Gap, some 3.000 feet higher, the days of frost weren’t nearly so distant. Temperature drops with increase of elevation, on the order of 3-5 degrees F per 1000 feet. So just as the greening of the land creeps northward, it also crawls up the mountains. Here, on the ridge line that marks the divide between Tennessee and North Carolina, the new leaves were bright green. In the Autumn, the progression will reverse, with leaves flaring and falling on the ridge before those in easterly Hendersonvile properly start to turn. So the southern Appalachians have growing seasons as short as those of Ohio or Pennsylvania. Yet with abundant rainfall and moderate sunlight, the mountains are mantled in lush growth.