In the deciduous woods of the northeastern U.S. and Canada, the progression of fall color typically follows lines of latitude. To catch all of fall, itinerant color chasers with too much time on their hands often start somewhere in Quebec in late September and then put in some serious road miles and six weeks of bed and breakfasts until they see the last leaves fall in New York and Pennsylvania sometime in early November. For fall color enthusiasts in the low deserts of Arizona, we have it decidedly easier. What color we miss in our own back yards, we can find in hours – if not minutes – with some relatively painless trips to the higher elevations that surround us. Subtract the obvious high-country opportunities like the Mogollon Rim and the White Mountains, and we’re still blessed with half a dozen “sky islands,” mountain ranges that rise nearly a mile, sometimes more, above local population centers like Tucson, Safford, Sierra Vista, and Globe.
What we lack in quaint covered bridges and idyllic scenes of white-steepled churches, we make up for in precipitous, windy roads that often lack guard rails but are sometimes paved, like those in the Pinaleno Mountains near Safford or the Catalinas north of Tucson, and dusty, rutted tracks that snake up to stands of aspen, gambel oak, and maples like Forest Service Road 651 in the Pinal Mountains south of Globe. This kind of vertical accessibility means that you can roll out of bed at 8am in Tucson and be sipping coffee and crunching through fresh layers of fallen leaves at nearly 9200 feet on Mt. Lemmon in the time that it takes a visitor to New Hampshire to correctly pronounce Lake Winnipesaukee. And you can do it again and again throughout the fall autumn season without burning vacation time, crossing any international borders, or stumbling over multi-syllabic words.
Fall in the higher elevations was late by a week or two this year which gave those of us with poor planning skills more of a grace period to see what we would have missed in previous years had the nights cooled down earlier and closer to schedule. Though late, the colors have been consistent and homogeneous with aspens and maples coloring up evenly and en masse, creating surreal environments of yellow on brown and yellow on white, like a colorized sepia photograph. A full description of the mechanics of why leaves change color is the lead story in the October Member newsletter that you should have received in the mail about a week ago.
Back at the Arboretum… the most vibrant trees that exhibit the anthocyanin pigments (the glorious oranges and scarlets of our Chinese pistachios), usually reach their peak in late November or early December. It’s a logical and predictable progression that begins with the now-changing leaves of honey locusts, jububes, and soapberries, all with their characteristic hues of yellow carotenoid pigments. In fact, all of the Arboretum’s deciduous trees lose their leaves by November or December, and most take on some sort of yellow-ish coloration first that ranges from the cornbread yellow of canyon hackberry to the lemon-sorbet leaves of our native cottonwood, the last hold-out to finally drop its leaves.
The fall season is much like following wildflowers in the spring but in reverse: the leaves are dying rather than springing to life – and summer is seven months away rather than two. It’s not a re-birth, it’s a cool-down. It’s the victory lap that celebrates the wrap-up of another desert summer and the out-pouring of sweat and air-conditioned tonnage that kept us cool enough to appreciate all of the color that we’ll see for the next few weeks. Think of autumn as a seasonal attitude adjustment. Chill.