Tropical House and glasshouses of the University of Vienna Botanical Garden (Botanischer Garten der Universität Wien)

The garden began in 1754 as a Hortus Medicus: prompted by her physician Gerard van Swieten, Maria Theresa had land bought on the Rennweg, and Robert Laugier laid it out before becoming its first director. Under Nikolaus Joseph von Jacquin, director from 1768 to 1796, it held around 8,000 species and grew to about 7.8 hectares. The cutting of the Jacquingasse between 1883 and 1890 reduced it to roughly 6 hectares.

The present glasshouse complex, Tropical House included, went up between 1890 and 1893 under Anton Kerner von Marilaun, who ran the garden from 1878 to 1898; only a few individual houses were added later. During the Second World War, its closeness to the Südbahnhof brought the garden more than forty bomb hits, forcing the demolition of the botanical museum and the felling of over 200 trees; repairing the damage took until the 1970s.

A general renovation of the institute and the glasshouses began in 1975. When it resumed in 1995, the Tropical House was opened to the public. In March 2010 the university closed the garden at weekends to save staff costs, but corporate sponsorship allowed it to reopen in April. Since January 2011 the garden has been a 'Core Facility' of the Faculty of Life Sciences.

The complex comprises 17 glasshouses covering about 1,350 m² according to the garden's website, or 1,500 m² according to Wikipedia, together with offices and work rooms. It stands near the main entrance, and its late-19th-century ground plan has survived largely unchanged.

The houses are run at different climates: cold, temperate and warm, kept humid, moderately humid or dry. The eastern houses hold bromeliads, orchids and tropical species, while the western ones are given over to plants of the dry tropics, cacti and other succulents. A gardeners' wing links the glasshouses, so that plants can be moved under cover in the cold season without damage.

The Tropical House sits at the heart of the group and is the only part open to visitors, although two windows offer views into the orchid and cactus collections. Near the entrance, a cool house (Kalthaus) shelters the cool-house group in winter; emptied in summer, it then serves as an exhibition space. An experimental glasshouse, built in the 1980s, completes the research facilities.

The glasshouses hold the core of the garden's collections: around 6,500 species and 17,000 accessions, more than half of all the species grown on the site. They serve research, university teaching and the conservation of threatened species.

Since the 1990s the Tropical House has grown an Aristolochia arborea raised from cuttings supplied by the Bogor botanical garden; its flowers, which mimic a fungus, appear almost every year. Since about 1950 the garden has built up a collection of Bulbophyllum orchids, now some 400 species and 2,500 plants, which Wikipedia ranks among the most important in the world; a few are on show in the Tropical House, the bulk in non-public areas. The garden's website also names Hoya and Freycinetia, black pepper (Piper nigrum), vanilla (Vanilla planifolia) and Dracontium pittieri among the glasshouse plants. On 29 May 2022 a titan arum reached full bloom, and the garden extended its opening hours for the following two days. In summer the cool-house plants, cacti, succulents and cycads are displayed outdoors.

The garden lies behind the botany department on the Rennweg and borders the Belvedere garden; the glasshouse complex is close to the main entrance. The Tropical House itself is a short visit, but the 8-hectare garden, with its ten outdoor display groups and its Alpinum, deserves an hour or two. In spring the Raritätenbörse, a rare-plant fair held every year on the third weekend of April, fills the garden with stands; summer brings free guided tours and exhibitions in the cool house. A visit pairs naturally with the Belvedere and its neighbouring alpine garden.