Return to Boyce Thompson Arboretum near Phoenix, AZ (May 2021)

The Boyce Thompson Arboretum (BTA) in Superior, Arizona is usually a quiet place. This week, however, it made headlines, but not the good kind: On June 7, 2021, the Arboretum was evacuated because of a raging wildfire nearby. Ultimately, the Arboretum was spared, but the Telegraph Fire had come perilously close to destroying Arizona's largest (392 acres) and oldest botanical garden (opened in 1929). The thought of losing so much history is terrifying, but it's a vivid reminder of how drought and wildfires have become the new normal in much of the West.

None of those things were foremost on my mind when I visited the Boyce Thompson Arboretum on May 19, 2021. It hadn't even been on my original itinerary, but I decided to take a more circuitous and scenic route to Tucson and swing by the BTA (see map below). That gave me an opportunity to take a selfie with my old buddies, these golden barrel cacti:

Probably the most popular selfie spot in the entire Arboretum!

As you can see on the map, the BTA is southeast of Phoenix (57 miles from the Desert Botanical Garden) and pretty much due north of Tucson (94 miles on AZ-79). While it's rarely mentioned in the same breath as the Desert Botanical Garden, the BTA is worthy destination in its own right. It may not have buzz of the DBG, but it's in a spectacular desert location away from the hustle and bustle of the Phoenix metro area.

Map of Arizona (Map data © 2021 Google)

As you can see on my BTA map below, there are many different sections and trails to explore. On my most recent visit, I briefly went to the Demonstration Garden (#7 on the map) and then took the mail trail to Ayer Lake (#20). I didn't have time for anything else.

Map of the BTA (© Boyce Thompson Arboretum)

I arrived at 11:30 a.m. so the light was really harsh. That's why I mostly took plant pictures and not many wider landscapes.

All-yellow prairie coneflower (Ratibida columnifera) and what I assume is Agave parryi

Prairie coneflower (Ratibida columnifera) with its typical colors

I have no clue which species of Opuntia this is, but I love the pure yellow flowers

Ferocactus peninsulae

It was a bit startling to see this clump of aloes happily blooming under a tree

View of Picketpost Mountain

Agave pelona

Echinocactus grusonii perfection

This sight always brings a smile to my face

This clump of golden barrels is even denser

Many of them were flowering

Echinocactus grusonii

Echinocactus grusonii flowers are small but golden in color, just like the spines

Agave ocahui

Boojum trees (Fouquieria columnaris)

Totem pole cactus (monstrose form of Pachycereus schottii)

Agave colorata with striking banding

This kind of banding is rarely seen on plants growing in a garden environment. The theory is that the banding is caused by the natural wax deposit being washed away during heavy monsoons.

Agave colorata

Agave chrysantha

Opuntia santa-rita

Opuntia santa-rita and Agave salmiana

Ayers Lake, a small man-made reservoir that supplies the Arboretum with water for irrigation (#20 on the map)

Cottonwood tree

Flowering saguaro (Carnegiea gigantea)

It's hard to get a close-up of the flowers since they're typically 6 ft. or more above ground

Opuntia spinulifera

Pets welcome

Whitethorn (Acacia stricta)

Aloe broomii, the most agave-like aloe

The display greenhouses in the Smith Interpretive Center (#13 on the map) are being rebuilt from the ground up. I look forward to seeing them in their completed state.

I have no idea what kind of tree this is, but it looks straight out of Middle Earth

Since visiting the Boyce Thompson Arboretum was a spur-of-the-moment decision on my part, I hadn't done any research and therefore completely missed their newest attraction: the Wallace Desert Garden. This 13-acre addition features almost 6,000 plants that were moved from the Scottsdale garden of H. B. Wallace, a well-known agriculturist who founded what would become the largest egg producer in the US. Starting in the 1980's, Wallace and his wife created a private desert garden, which continued to grow both in size and scope. After Wallace's death in 2005, his family realized they wouldn't be able to maintain the garden and approached the BTA about moving the collection. The transfer of plants began in 2016 and was finally completed this year. This article is a fascinating account of this multi-year project.

Unfortunately, I missed the Wallace Desert Garden, but I'll make it a priority on my next Arizona trip. By then, the plants will have had a chance to get settled even more.


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  1. Fabulous! Great memories of my last trip to AZ and visit to the BTA.

    1. I still kick myself for missing the new Wallace Desert Garden. It's off beyond the Demonstration Garden.

  2. Great photos despite the harsh light conditions. Thanks for explaining why my Agave colorata has not produced those wonderful stripes - there are no monsoonal rains here :(

    1. Same here. I've never gotten that banding on any Agave colorata, zebra, etc. Disappointing but just another fact of life :-)

  3. The addition of the Wallace collection is such exciting news! Can't wait to visit, maybe when it cools down in October...

    1. I can't wait to see it either. I'm beyond happy the BTA wasn't damaged by the wildfire.

  4. Always good to save something for future trips. Looking around at the landscape it seems so barren as compared to a northern forest. Hard to imagine wildfires creating havoc.


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