In his Manual to Accompany the Map: Potential Natural Vegetation of the Conterminous United States, A.W. Küchler writes that “a French botanist, taken to the heart of the desert in Nevada, asked his guide when they might expect to reach the desert!”
Küchler was making the point that Americans may interpret the word “desert” quite differently from some Europeans. We’re accustomed to labeling a landscape with a scattering of shrubs and cactus as desert. The Frenchman, who may have visited the Sahara and witnessed no vegetation at all, was expecting something quite different. He would have been mystified by Arizona’s “desert” as well, with its prickly pears, agaves, mesquite, sage brush, etc. Way too much vegetation.
Arizona is by no means totally desert, even going by the broader American definition. Roughly three times the size of Virginia, ranging in altitude from 100’ to over 12,000’, with precipitation as low as 3” annually and as high as 40”—much of it falling as snow in the latter case—Arizona supports several vegetation types, many visible in a three-hour drive from Phoenix.
Starting in the capital city (elevation 1,000’, precipitation 8”) and heading north on Interstate 17, you first pass through what we’ll call desert, even if plants are decidedly present. Creosote bush and white bur sage predominate, with considerable open ground between plants. Small trees such as the palo verde and mesquite occasionally protrude from the shrubs. And this is where you’ll find the iconic giant saguaro, aka the Monarch of the Desert.
The highway gradually climbs leaving Phoenix, but the ascent becomes steeper and more winding as you approach 3000’ elevation. (The Arizona Department of Transportation kindly marks each thousand-foot interval.) Fairly abruptly, you’ll emerge onto a mesa covered with grasses and shrubs. As you travel over the mesa, occasional gorges reveal the dark volcanic rock underneath.
As you head north, the terrain undulates between 3,000’ and 4,000’, and the vegetation becomes gradually more dense, with many juniper shrubs. As an alternative to continuing on I-17 to Flagstaff, take AZ Hwy 179 north to Sedona, known for its stunning red rock formations. At this 4,400-foot elevation you’ll find a mix of junipers, pines, dwarf oaks, agaves and yuccas, as well as many grasses, all supported by 19” of precipitation. The plants’ foliage comes in a pleasing variety of colors—dark green, light green, blue-green and yellow-green. (See the accompanying photo of an agave poking out from the manzanita shrub.)
Continuing northward from Sedona on AZ Hwy 89A takes you up through Oak Creek Canyon, where the stream supports comparatively lush vegetation—cottonwood, sycamore, maple and willow. Eighteen miles north of Sedona, the highway ceases its leisurely wind along Oak Creek and jumps to the hillsides, following a series of dizzying switchbacks up to the Colorado Plateau. Here at almost 7,000’ you’re in the Ponderosa pine forest, a much colder, wetter place; Flagstaff averages about 100” of snow annually.
Taking US 180 northwest out of Flagstaff, then turning right on N. Snowbowl Road will take you up to the 9200’- high Arizona Snowbowl in the San Francisco Peaks; from there you can ride the chairlift to 11,500’. By now you’re in spruce-fir-quaking aspen forest, with alpine wildflowers at the woods’ edge.
If you’re really hustling you could make this entire trip in one day, but it would be more relaxing to break it up with an overnight in Sedona or Flagstaff to better enjoy the scenery and plant life.
Arizona Gardens
Desert Botanical Garden
Only about 15 minutes northeast of Phoenix’s Sky Harbor Airport, the Desert Botanical Garden lies within Papago Park. Its 140 acres house more than 27,000 individual plants, comprised of more than 4,400 different species. The DBG is recognized as a true botanical garden, meaning that they keep records on all their plants, sharing this information with sister institutions around the world.
Several fully accessible trails traverse the garden, each following a certain theme. The Sonoran Desert Nature Loop Trail focuses on the local flora, while other trails lead through plant collections from South America, Baja California and Australia. The Plants and People of the Sonoran Desert Loop Trail highlights the complex relationships that Native American people and European settlers had with these plants.
Boyce Thompson
Arboretum State Park
About a hundred years ago mining engineer William Boyce Thompson began amassing a fortune in the copper mines of southeastern Arizona. Fond of the area, he decided to build a winter home and establish an arboretum in the small town of Superior, 75 miles east of Phoenix on US Route 60.
The 392-acre Boyce Thompson Arboretum now houses more than 3,400 plant species from arid regions around the world. An accessible trail winds through the arboretum’s natural areas along Queens Creek and beneath the shadow of Picket Post Mountain. Other paths take you through a cactus garden, a palm grove and a eucalyptus grove containing one of the largest red gum trees in the world.
One of the saddest prospects in the gardening world is the possible loss of a significant garden. The Wallace Desert Garden in Scottsdale, Arizona was founded in the 1980s but came into peril in 2005 after the death of Henry B. Wallace. As his endowment was running out, plant enthusiasts tried to find someone who could save the Wallace Garden. The Boyce Thompson Arboretum stepped forward and began digging over 5,000 plants that had to be removed by 2017. Very large specimens, up to 25’ tall, were put into 6’ x 6’ boxes built around the root ball, then trucked to Superior. Following considerable planting effort at their new home, the Wallace Desert Garden at BTA will officially open on March 28, 2020, so time your visit accordingly.
Tucson
Not to be missed in the Tucson area is Saguaro National Park, with its signature cacti. The Tucson Botanical Garden is a small retreat in the heart of the city. Drop in if you happen to be close by. Probably of more interest to out-of-town visitors is the Tohono Chul Gardens, Galleries and Bistro. Using their words, it’s a “fusion of nature, art and culture.” I haven’t visited it as yet, but look forward to doing so on my next visit to Tucson.
And I won’t be too upset if I can’t find “the desert.”
