Dow Gardens Conservatory

The conservatory's story is bound up with that of the family estate. In the spring of 1899 Herbert Henry Dow, who had founded the Dow Chemical Company two years earlier, began improving the land around his future Midland home: he planted an orchard and later built a barn and a first greenhouse for his plants. After his death in 1930 his widow Grace set up the Herbert H. and Grace A. Dow Foundation, which still owns and runs the gardens; for the next forty years or so they were simply maintained.

From 1970 the foundation, led by Herbert Henry Dow II, resolved to turn the property into a first-rate botanical garden. Landscape architect John W. Campbell delivered a master plan in December 1974, and the founder's son, the architect Alden B. Dow, oversaw a three-year revitalisation during which he added bridges, a first visitor centre and a new greenhouse to replace his father's. Working drawings were completed in October 1975 with Roper/IBG Greenhouse Consultants, and Dow Regional Construction and Development Corporation acted as general contractor. The greenhouse opened to the public in spring 1976, and the gardens officially reopened in 1978.

Now known as the Conservatory, the building went through a major renovation and expansion that was completed in autumn 2022; it reopened on 4 October that year.

Alden B. Dow gave the greenhouse a low, ground-hugging profile, which the archive of his home and studio holds up as a fine example of his way of merging landscape and architecture. The plan is a square of 64 feet a side (about 19.5 m), or roughly 4,100 square feet (some 380 m²). Wide windows stand on concrete-block foundation walls and lean outwards to meet the edges of a shallow pyramidal roof made of glass and aluminium panels. As first built, the interior had brick pavers in the main space, a divided growing area, a workroom and a mechanical and storage room.

The 2022 renovation replaced all 432 roof panels with low-emissivity double glazing, and the outward-sloping side walls received a further 62 panes. A high-efficiency heating and ventilation system now adjusts itself to the temperature and humidity inside and out. The display space, formerly split into three rooms, has become a single open volume, reached through a bright new lobby and an inner vestibule that keeps the butterflies from escaping.

The conservatory holds a tropical planting of flowering plants, vines, small trees and aquatic species, which the horticulture team changes from season to season. Since 2022 a concrete water feature with nine falling spouts and built-in planters, lit by LEDs, has formed the centrepiece of the room.

The highlight of the year is Butterflies in Bloom, a spring exhibition (March to April) described as the most popular on site, in which thousands of butterflies from around the world move among the plants. Paused for two years before the 2022 reopening, it now has its own section for butterflies and chrysalises. A window added during the works offers a close view of metamorphosis and of the exhibit preparation that normally happens out of sight.

The conservatory is part of a visit to Dow Gardens, a 110-acre (about 45 ha) garden that now receives between 200,000 and 250,000 visitors a year. Allow half a day to combine it with the 1,400-foot (about 430 m) canopy walk through Whiting Forest and a tour of The Pines, the former Dow family home. Spring, when the butterflies are in residence, is the best season, and the garden also holds a Halloween Hike in October and a Christmas Walk in December. A few hundred metres away, the Alden B. Dow Home and Studio offers tours that round out an introduction to the architect's work.