Smith Building display greenhouses (Boyce Thompson Arboretum)

Boyce Thompson Arboretum was founded in 1924 near Superior by William Boyce Thompson (1869-1930), an engineer, financier and copper magnate. Its first administration building, completed in 1926 and flanked by two Lord & Burnham greenhouses, is the Smith Building: the firm designed and built it from 1925 using stone from local quarries, and the arboretum dates its completion to 11 August 1926. It served as reception, research laboratory and greenhouses, and has carried the name of William T. Smith, board chair and CEO from 1963 to 1986, since 1979. The East Greenhouse was first planted with cacti, the West Greenhouse with succulents from other plant families. The arboretum as a whole has been on the National Register of Historic Places since 26 March 1976.

By 2018 the greenhouses had deteriorated so far that visitors could not enter, and the historic cactus collection was at risk. The arboretum then partnered with a firm specialising in restoring Lord & Burnham greenhouses, which had acquired the firm's engineering plans, tooling, copyrights and trademarks. The rebuild follows the original design, with modern materials and energy-efficiency upgrades. A 2021 campaign document puts the project at $350,000, including $100,000 in matching funds from the board. A members' preview was held on 17 October 2021 and the greenhouses opened to the public the next day.

The Smith Building is a local-stone building of 3,600 square feet (about 334 m²) according to the arboretum, with two symmetrical greenhouses, East and West, on either side.

The 2021 rebuild follows the original design with modern materials. The campaign document issued before the works describes the programme: a concrete cap on the existing stone kneewall, gable ends with commercial doors, white powder-coated extruded-aluminium framing, ClearSpan scissor trusses that clear the interior of posts, sidewalls and gable walls of 3/16-inch (about 4.8 mm) clear tempered glass, and a roof of 8 mm clear triple-wall polycarbonate (76% light transmission). Motorised ridge and side vents under thermostat control, circulation fans and LED grow lights hung from the trusses complete it, engineered for 20-pound-per-square-foot loads and 105 mph gusts. That document describes a plan; the official photographs on the Smith Building page show a white frame, clear glass walls and a gabled roof of translucent panels with a cellular look, in line with the plan.

Inside, the plan called for wheelchair-accessible curving paths, contoured beds held by gabion walls and, at each end, a succulent "fountain".

The East House holds cacti and other succulents native to the Eastern Hemisphere, the West House those of the Western Hemisphere. The arboretum points to rare and unusual species among them, some of them frost-sensitive. According to the 2021 campaign document, the greenhouses let plants of conservation concern be displayed to the public and then secured overnight: poaching of cacti and succulents is rising with commercial demand, and such specimens could not be replaced because of CITES rules. They also shelter more tropical species that could not survive outdoors on the site.

An arboretum page on May blooms mentions a large Adenium, 'Crimson Star', a popular early hybrid whose heritage traces to the arboretum. Outdoors, a cactus and succulent garden below Magma Ridge gathers succulents from deserts of North and South America.

The two greenhouses flank the Smith Building and are visited with arboretum admission: the arboretum invites visitors to walk through the greenhouses that have inspired botanists and horticulturists for generations. The Heritage Rose Garden adjoins the building.

The rest of the site fills a day: the Wallace Desert Garden, opened to the public on 1 October 2020, the cactus and succulent garden and the trails of the Queen Creek canyon. The arboretum is open daily in autumn and winter. The arboretum holds plant sales, including a fall sale announced for 17 October to 1 November 2026.