Fall Colors on the Coconino (updated weekly)
October 23, 2013
Colors are in full splendor on the Coconino National Forest. Many of the trees in the higher elevations near Flagstaff are a past their prime but views are still beautiful. The maples on the Mogollon Rim District are also passing their prime but still worth the visit, and the deciduous trees in Oak Creek Canyon and the Sedona area are spectacular right now. Don't forget to check out pictures on our Fall Colors set on Flickr!
*Note: While Oak Creek Canyon and West Fork Oak Creek are a popular locations near Sedona to see fall colors, they're not the only places to visit and parking is very limited! There are plenty of other equally goreous leaf-peeping locations including hikes along Casner Canyon, Allen's Bend Trail by Oak Creek, and Girdner Trail along Dry Creek west of Sedona. The Crescent Moon and Chavez Crossing areas are also wonderful!
Other suggested sites
Flagstaff Ranger District:
Hart Prairie (Accessed via Hwy 180 and Forest Service Road 151 and/or FSR 418, which also loops around the north end of the Peaks for a pretty view)
Aspen Loop Trail (Via Highway 180 and Snowbowl Road) or the AZ Trail that stretches from the Aspen Loop Trail north through Hart Prairie
Mogollon Rim Ranger District (north of Pine and Strawberry near Blue Ridge):
FSR 321 aka “Dane Ridge” (Hwy 87 to FSR 95 next to the Mogollon Rim Ranger Station, right on FSR 96, right on FSR 321)
FSR 300 aka “Rim Road” or “General Crook Trail” (Hwy 87 or Hwy 260 to FSR 300, 2.5 miles east of Hwy 260, 10 miles north of Strawberry)
Cabin Loop Trail
The photos above were taken on Sept. 25, 2012 on the Inner Basin Trail by Brienne Magee. Click the image for a larger view. See other photos on Flickr.
Changing leaves herald the coming of autumn to the Coconino National Forest as early as mid-September. That's when forest roads and trails begin to hum with the crowds of nature lovers who come to enjoy the display. The Coconino encompasses such a broad range of habitats that it's possible to stretch this most colorful of seasons into more than a month of celebration within its boundaries. The gold rush begins on the higher slopes of the Forest's volcanic highlands as the aspen leaves change to amber while summer is still in the air. From there, the transformation gradually migrates to the crimson sumacs and fuchsia maples of the desert canyons as brisk nights confirm the full onset of autumn. The climax of this parade of color generally occurs around the second week of October, but remnants of reds, oranges and golds can linger in the canyons as late as mid-November.
What Makes Leaves Turn Colors?
The leaves on deciduous trees do not really “turn” colors. They just lose their green. Leaves actually begin to prepare for autumn in the spring. At the base of each leaf is a layer of cells called the “abscission” or separation layer. All summer, small tubes pass through the abscission to carry water into the leaf. The leaf uses this water with carbon dioxide, sunlight and chlorophyll to produce food. This process is called photosynthesis.
The word photosynthesis means “putting together with light.” The food, or “sugar,” is carried back out through the tubes in the abscission into the tree.
In the fall, the cells of this abscission layer begin to swell and form a cork-like material, reducing and finally cutting off flow between the leaf (leaves) and the rest of the tree. Also, because of cool nights, the sugar still produced in the bright fall sun is not readily transported from the leaves to the stems and roots. The less sunlight (shorter days at the end of summer, beginning of autumn), the less green chlorophyll is produced, and is, in fact, broken down.
This is when you begin to see the yellow xanthophyll and orange carotene that are present in the leaf all year around but are covered by the green chlorophyll. No one is sure what purpose these other elements serve, but scientists believe they also have something to do with photosynthesis. Certain species of deciduous trees will begin, at this time of warm days and cool nights, to produce anthocyanins. Anthocyanins are the reds and purples and are produced only in autumn; they are not present in the leaves all year.
During this dormant period, the trees use the reserves they have stored up over the summer to stay alive. They need this time to take a rest from producing.
What do autumn leaves and bananas have in common?
The green color in unripe bananas comes from chlorophyll, the same pigment that gives green leaves their color. As bananas ripen, the chlorophyll breaks down and disappears, revealing the yellow color, which has been there all along. The yellows and oranges of autumn leaves are also revealed as their chlorophyll breaks down.
Why Is It That Some Years We Get Great Color And Relatively Bland Results In Other Years?
Good reds are produced when the days are warm and sunny and the nights are cool (45°F or less, but not a frost), coming one after another. In this setting, the leaves produce lots of sugar using the abundant sunlight, but the cool nights prevent the sugar from flowing through the leaf veins. At this point, anthocyanins (the reds and purples) are produced. Yellow and orange are fairly constant, because they are already in the leaf and do not require specific weather situations.
A warm, wet period in the fall will cause the changing to be not so brilliant because sunny days producing the sugar and cool nights halting it’s spread produce the best color. A severe frost will kill the leaves, ending the show immediately.
Why Is It That Some Portions Of The Mountain Or Flagstaff Get Better Color Results From The Changing Leaves?
Sunshine is the key. The more sunshine, the more sugar is produced. While there will not be enough sunshine to produce chlorophyll, some sugar and anthocyanins (the red/purple/blue colors) will be produced as a last ditch effort to bring nutrition to the leaves. In trees where anthocyanins are not produced, we will see only the yellows and oranges.
The sunnier spots of the mountain and less-shaded trees in town will become reddish/purplish, if they are predisposed to do so. In addition, a single tree may be red on one side, the side more exposed to the sun, and yellow and orange on the other.
When Do The Leaves Typically Change Color In Flagstaff? Closer To The Peaks?
Typically, trees in the highest elevations begin to change mid-September. Then, like a slow-moving wave, the color descends into town. The show usually ends in late October.
What Are The Types Of Trees In Northern Arizona That Turn Colors?
Aspen (yellow), Maple (yellow, orange, red), Oak (yellow, orange, brown), Cottonwood (yellow), Various fruit trees (red, orange, yellow), Elm (yellow), ash (yellow), poplar (yellow), willow (yellow), and even weeds and bushes like sumacs (Orange, red) and poison ivy will change colors and decorate the roadsides.
What Makes Evergreens…Well, Evergreen?
Evergreen trees (pines, spruces, cedars and firs) don’t lose their leaves in the fall. They are covered with a heavy wax coating and the fluids inside the cells contain substances that resist freezing. Evergreen leaves can last for several years before they fall and are replaced by new growth. They may, however, become brownish if the winter is particularly cold.
Fall Color Hotline
The Fall Color Hotline is active from mid-September through mid-November and is updated weekly. Call toll-free: 800-354-4595.