Boyce Thompson Arboretum, Getting To Know You

Boyce Thompson Arboretum is the largest and oldest arboretum in Arizona and one of the oldest and largest arboretums west of the Mississippi River. It is the oldest non-profit research institution in Arizona. It was founded in 1924 by William Boyce Thompson, who owned many mines around the world, including the Magma Copper mine in Superior, AZ. It was in Superior that he fell in love with the Sonoran Desert.  He built a home here and acquired almost 400 acres of land.

In 1924 he began work on the Boyce Thompson Arboretum as a living museum of the Sonoran Desert and a plant research facility.  Desert Plants, a research journal published in conjunction with the University of Arizona, still comes out monthly. 

The Arboretum is 343 acres in size.  It has administration buildings, historically significant buildings, including the Smith Interpretive Center and Display Greenhouses, a visitor center and gift shop, and the usual maintenance and plant propagation areas. There are plants here from the United States, Mexico, Australia, Madagascar, India, China, Japan, Israel, South America, the Middle East, Africa, the Mediterranean, and the Arabian Peninsula.  It was placed on the National Register of Historic Sites in 1982.

There are 4.7 miles of trails which pass through various desert areas and some shady areas.  Two trails go up Picket Post Mountain.  Many plants, as one would expect, are labeled with their name, both Latin and vernacular.  Along with specific garden areas, such as the Sonoran Desert and Australian areas, there is a Pollinator Garden, two rose gardens, a Children’s Garden, the Demonstration Garden, and the Wallace Garden which opened in the fall of 2020.  There are 3,900 plant species, of which 405 are rare and/or endangered.  Many of the plants seeds, specifically from the Desert Legume Program at the Arboretum, have been placed in the Svalbard Global Seed Bank

The Arboretum is also home to Mr. Big, one of Arizona’s Champion Trees and one of the largest of its kind in the United States.  Mr. Big is a Red Gum or Long Beak Eucalyptus tree.  He came here in 1926 when he was only 3 years old.  Since then, he has grown to 145 feet tall with a trunk diameter of 266 inches. 

The Arboretum is in a riparian area between the mountains with two creeks, which are usually dry.  Thus, is it home to many other liiving organisms like rabbits, snakes, bob cats, cougars, vultures, ravines, tarantulas, scorpions, and other critters.  Over 275 species of birds have been spotted here making it “Most Enchanting” by the Audubon Society. 

Plan a day to see it all or, in the hot summer, come early – summer hours are 6 a.m. to 3 p.m. – on two separate days.  Admission is $15.00 for adults, $5.00 for ages 6-12, those under 6 are free.  There are discounts for military personel and veterans as well as medical first responders.  Wildfire fighters enjoy the Arboretum for free as a token of the Arboretum’s appreciation of their efforts to prevent the spread into the Arboretum of the June, 2021Telegraph Wildfire which spread over 180,000 acres and, while 90% contained, continues to smolder and burn until ground wetting rain extinguishes it.

I am most appreciative of being able to volunteer here for the summer.  It is truly an oasis of unique plants and animals.  I also want to thank the following people for helping me to learn about Superior, the desert, and the Arboretum, its history, its plants and animals, and some of their propagation techniques Shelby, Lynnea, Preston, Chris, Sylvia, Dr. Bobbi, and the rest of the staff.  They are a warm, welcoming group of people who it is an honor to get know and who work to continue the vision of Mr. Thompson.