Show Houses (Schauhäuser) of the Heidelberg University Botanical Garden

Heidelberg's botanical garden began in 1593 as a medicinal garden (hortus medicus), created near the castle by the physician Henricus Smetius. It changed site several times: a fifth garden was established in 1834 under Gottlieb Wilhelm Bischoff, and a sixth in the late 1870s under Ernst Pfitzer, who gathered his orchid collection there. The seventh, the present one, opened in 1915 on the Neuenheimer Feld campus; Wikipedia credits Georg Albrecht Klebs and head gardener Erich Behnick. The university's centenary press release describes it as a strictly geometric site with imposing show greenhouses. Shortly before the end of the war bomb strikes destroyed most of the plant stock, including Pfitzer's collections; the English version of the official site speaks of a total loss of the greenhouse collection, a famous orchid collection among it.

The postwar decades were a period of rebuilding, above all under Werner Rauh, director from 1960 to 1982, and his scientific head Karlheinz Senghas. Glass area grew gradually to 4,000 m² according to the garden's own site, 4,800 m² according to the 2015 press release, while the garden, once 3.9 hectares, lost about a quarter of its grounds to university institutes as early as the 1970s.

The renovation, announced as early as 2015, aims to uncover the original façade of the 1915 complex. Temporary glasshouses for the plants were set up from April 2023, and the official launch ceremony took place on 21 July 2026. The research glasshouses, about 2,500 m² for some 26.3 million euros, come first (works ending in late 2028); renewal of the show houses is planned from October 2029, and the whole garden is due to be complete in September 2033.

The 1915 complex included, at the southern end of the garden, a long orangery-style building, now almost entirely hidden by four glasshouses added in front of its façade, separated by gaps that energy efficiency no longer tolerates. At the centre stands the large Tropenhaus, flanked on both sides by show houses; according to a tourism website, a Victoria-Haus holds the aquatic plants. The renovation answers a long list of defects: rust, leaks, energy-poor single glazing, faulty shading systems and wired glass in the roofs that has become brittle.

The plans by Haas Architekten called for removing the glazed additions to free the historic façade, then building show, research and collection houses on about 2,600 m², around an inner courtyard with the Victoria-Haus at its centre. An examination showed that the orangery-style buildings have no foundations: they will be rebuilt in the old style, and the Tropenhaus will keep the same volume as the present one, according to the 2023 announcement.

The living collection comprises about 13,000 accessions representing 4,800 species or subspecies according to the official site, whereas Wikipedia gives more than 14,000 species. Its historic core collections, tropical orchids, bromeliads and dry-climate plants from Madagascar, are official research and conservation collections supervised by the Regierungspräsidium Karlsruhe. Wikipedia lists eleven special collections under glass: Old World, Madagascan and New World succulents, tropical orchids, bromeliads, cycads, insectivorous plants, tropical ferns, Aristolochiaceae, Cyclanthaceae and Mediterranean geophytes.

Only a small part of the glasshouses can be visited without an appointment, according to Wikipedia. The show pavilions include a Bromelienschauhaus and a Sukkulentenschauhaus; a tourism website also mentions a tropical mountain-forest house, a cold house with Mediterranean and carnivorous plants, and the Victoria-Haus, devoted to marsh and water plants. Many of these historic holdings come from Werner Rauh's expeditions.

The show houses stand on the Neuenheimer Feld campus, near the university hospital; admission is free, as it is to the open-air garden, which is open all year. The official site warns that some parts may be temporarily inaccessible because of the works, and that the "Botanischer Garten" bus stop has been removed during construction: the stop to use is "Campus im Neuenheimer Feld". The works planned from October 2029 are due to transform the show houses substantially.

The programme includes drawing and watercolour sessions under glass and torchlight tours, "Nachts im Gewächshaus", in November and December 2026. The neighbouring arboretum and systematic garden complete a visit; the official site recommends the zoo car park, a minute or two on foot away.