Glasshouses of the Ecological-Botanical Garden (ÖBG), University of Bayreuth

The Ecological-Botanical Garden (Ökologisch-Botanischer Garten, ÖBG) was founded in 1978 as a central scientific institution of the University of Bayreuth, focused on ecology and the environment. Its first director, Günter Rossmann, later founded the Rossmann Palaeobotanical Foundation. Construction of the glasshouses began in 1985 and was completed in 1993 with the house for tropical high-mountain plants; the heated basin for tropical aquatic plants came into use in 1995.

The high-mountain house grew out of research that Bayreuth botanists led by Erwin Beck had been carrying out since 1979 on the flora of the East African mountains and on how plants adapt to conditions there. Under Rossmann's direction, early results of this work were used, in cooperation with the Technical University of Munich, to define the climate and soil of the house, which entered service in 1994.

The forest scientist Gregor Aas directed the garden from 1996 to 2023. In 1997 the garden opened to the public, at first on Sundays only, with guided tours on set themes. In 1999 a Lobelia rhynchopetalum grown in the high-mountain house since 1994 flowered, the first time the species had bloomed in cultivation anywhere, which allowed its floral biology to be studied under controlled conditions; German Wikipedia dates the flowering to 2000. Since 2008, Cuban whistling frogs (Eleutherodactylus ricordii) have lived in the tropical forest house.

The garden describes its glasshouses as its architectural centrepiece. German Wikipedia puts their area at about 6,000 m², with six show houses of different climates linked by a circular route; an entrance hall hosts temporary exhibitions, and an overwintering house shelters the container plants in the cold season.

The house for tropical high-mountain plants is the most technical. It is small, with 74 m² of floor space, 50 m² of it planted, and a height of 4 m, and it reproduces the frost-alternation climate of summits above 3,500 m, where temperatures vary more over a day than over a year. All year round, day and night last twelve hours each, and the temperature climbs from 0 °C at around 6-7 a.m. to 20 °C at around 2 p.m.; colder nights would be possible but are avoided to save energy. For thermal insulation the house is enclosed by a closed space with its own temperature control. Supplementary lighting, which completes the twelve-hour day in winter, uses up to 52 lamps, 28 metal-halide lamps of 1,000 W and 24 sodium lamps of 400 W, housed in a temperature-controlled lamp room separated from the glasshouse by a glass ceiling.

More than 5,000 tropical and subtropical species are grown under glass. The circuit passes through tropical dry forest, mangrove, lowland rainforest, cloud forest and the threatened laurel forest of the Canary Islands, and a basin holds tropical aquatic plants.

The high-mountain house gathers giant rosette plants from the South American páramos (Puya alpestris, Espeletia) and above all from the mountains of Africa: Senecio kilimanjari, Lobelia deckenii, L. keniensis, L. telekii and L. rhynchopetalum. They grow alongside tussock grasses, cushion plants such as Helichrysum, rosette plants such as Haplocarpha rueppellii and dwarf shrubs such as Alchemilla argyrophylla. The Ethiopian lobelia, which flowers only once, produced an inflorescence several metres tall bearing thousands of flowers that bloomed for about six months. Wollemia nobilis is among the other rarities in the glasshouses.

The garden also keeps several thousand container plants from the Mediterranean and the subtropics of Australia, Asia, the Americas and Africa: they winter in a cool glasshouse and spend the summer outdoors in front of the glasshouses.

The glasshouses stand on the University of Bayreuth campus in Upper Franconia, within a 16-hectare garden that holds some 12,000 species. The outdoor areas continue the journey: a plant-geography section leads through recreated woodland, heath, bog, steppe and dune from North America to China, Japan, Korea, the Himalayas and Europe. To the south, the crop garden shows more than 700 species and varieties each summer, next to a medicinal plant garden and an orchard grazed by sheep.

Summer is the best season to see the container plants set out in front of the glasshouses. The garden regularly runs guided tours, talks and events, such as, in 2026, the Week of Botanic Gardens in June and the Bayreuth Mushroom Days in October.