The six-acre Cactus and Succulent Garden has its roots in the beginning of Boyce Thompson Arboretum itself—the first cactus and agaves were planted here in the early 1920’s.
Over the years the collection has expanded, and now features around 1,500 plants from the southwestern United States, Mexico, and South America in its forty rock-bordered beds just off the main trail.
The Cacti
Over two hundred species of cactus are represented here, one third of which are threatened with extinction in the wild. Forests of large columnar cactus including the native saguaro (Carnegiea gigantea), the Mexican fencepost cactus (Pachycereus marginatus), the organ pipe cactus (Stenocereus thurberi), and the South American cardón grande (Echinopsis terscheckii) dominate the heights, forming an impressive forefront against the skyline. Over twenty species of barrel cactus can be observed at their feet, including many sizable specimens of the golden barrel cactus (Echinocactus grusonii). Scattered throughout the garden are fifty species of prickly pear and cholla, ranging from small clumps of the bright purple Santa Rita prickly pear (Opuntia santa-rita) to the tree-sized Indian figs (Opuntia ficus-indica). In the understory, not to be ignored, are the smaller cacti. Thirty-three species of pincushion cactus (Mammillaria spp.), twenty-one species of Easter lily cactus (Echinopsis spp.), and ten species of hedgehog cactus (Echinocereus spp.), including both the locally endangered Arizona hedgehog (Echinocereus triglochidiatus var. arizonicus) and our very own Boyce Thompson hedgehog (E. boyce-thompsonii), present an assortment of forms. From late spring through early summer, hundreds of cacti in the collection put on a dazzling display of blooms.
The Succulents
The garden also features around 130 plant species categorized as succulent or semi-succulent. Forty-four different species of century plant (Agave spp.) grow here in sizes ranging from the small, compact Toumey’s agave (Agave toumeyana) to the massive American century plant (Agave americana). Six of the garden’s agave species, famous for only blooming once in their lifetimes, are threatened with extinction in the wild. Also featured in the collection are several large boojum trees (Fouquieria columnaris), one of which was wild-collected from Mexico in 1925. Now over thirty feet tall with a girth of around three feet, it is considered one of the largest specimens of its kind in the United States. Other notable plants include thirty large Yuccas, even a many-branched Joshua tree (Yucca brevifolia), and, for the discerning eye, several specimens of the diminutive and rare native San Francisco River leatherpetal (Graptopetalum rusbyi).
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Ever wonder who really keeps the desert blooming?
It’s Pollinator Awareness Week — and we’re spotlighting the hidden heroes of the Sonoran Desert. From bats on the night shift to bees burrowing in the dirt, their stories are wild.
Follow along all week — and discover what’s buzzing, fluttering, and swooping through our garden.
#PollinatorWeek #SonoranDesert #boycethompsonarboretum
Calling all teachers! Boyce Thompson Arboretum invites you to join us for our professional development sessions. Come spend time with us as we familiarize ourselves with the 5E Instructional Model and explore desert plant adaptations! Pre-registration is required. Space is limited. Visit https://btarboretum.org/pd/to apply.
✨Summer Golf Cart Tours ✨
Explore the arboretum this summer with our staff on a golf cart tour! We invite you to join us for an hour long cart ride to some of our most scenic spots of the arboretum. Our knowledgeable staff will give you insights into our collections and take you to the best photo ops the gardens have to offer.
Wednesdays-Saturdays in June, July, August between 7:00am-8:00am, 9:00am-10:00am, 11:00am-12:00pm
Cost: $20 per person, plus the cost of admission.
Cart tours are first come first served with a limit of 5 guests. Ask about availability at our Visitor’s Center Wednesday through Saturdays this summer!
Some exclusions apply
Make the most of your mornings this summer! From June through August, Boyce Thompson Arboretum is open Wednesday through Monday, 6:00 a.m. to 12:00 p.m., with last admission at 11:00 a.m. We are closed on Tuesdays.
Plus during these months enjoy special admission rates:
Ages 13 and up – $16
Children 5–12 – $10
Children under 5 – Free
Visit early, explore the trails, and soak in the beauty of the Arboretum in the cooler part of the day.
Tiny cuttings, big impact.
Every plant you see here started from just a snip — carefully cleaned, dipped, and rooted with care. Propagation isn’t just practical. It’s powerful. It helps us grow more plants for pollinators, restoration, and education — all while conserving precious resources.
But we can’t do it alone. Your support helps us expand our propagation efforts and grow the future of this garden.