Pflanzenschauhaus (Plant Show House), Luisenpark

The Luisenpark took shape at the end of the nineteenth century: a ten-hectare lower park was laid out in 1892 and a twenty-hectare upper park in 1897, and in 1896 the whole was named after Louise of Prussia (1838-1923), Grand Duchess of Baden, daughter of Emperor Wilhelm I and wife of Grand Duke Frederick I. A first palm house, 42.5 m long and 16 m wide, was built there in the early twentieth century: for the great art and horticulture exhibition of 1907 according to the journal Garten + Landschaft, in 1908-1909 according to Wikipedia. It was destroyed in the Second World War.

Its successor, the Pflanzenschauhaus, opened in 1958. It was enlarged in 1975, when the park, extended to 41 hectares, hosted the Federal Garden Show, and again in 1986, 1989 and 1996, when the butterfly paradise opened; the tree-fern house followed in 2009.

As the 2023 Federal Garden Show approached, demolition was considered and rejected: for the park's director, Joachim Költzsch, the building shaped the character of the Luisenpark too strongly to go. A renovation costing more than 3 million euros was entrusted to the general contractor Rabensteiner, as part of the redevelopment of the Neue Parkmitte designed by Bez+Kock Architekten and Koeber Landschaftsarchitektur, winners of the 2018 competition. The Neue Parkmitte opened on 14 April 2023, with the start of the garden show.

The Pflanzenschauhaus is a post-war glasshouse ensemble made up of four parts: the large and the small show house, the tree-fern house and the butterfly house. Through successive extensions it has reached a total area of about 2,700 m², which also includes a cactus house and spaces for aquariums and terrariums.

The renovation carried out before 2023 changed both its appearance and the way it works. The clouded twin-wall sheets were replaced by double insulating glazing with solar protection, the most visible change. Heating now relies on warm-air units and fans, ventilation on ridge and side openings, all controlled by a central climate computer linked to sensors that sets the temperature between 18 and 26 °C according to the plants' needs. Wiring, irrigation and roofing were renewed, and the foyer was opened up towards the Neue Parkmitte. Between the glasshouse and the Kutzerweiher pond, a polygonal grotto in the basement of a new building houses an underwater world of some twenty aquariums.

The two large halls display tropical and subtropical plants, among them coffee shrubs, rubber trees, giant bamboo and orchids. The cactus house holds about 400 cacti and 250 other succulents, and the tree-fern house, opened in 2009, completes the botanical circuit.

The complex is also something of an indoor zoo. Since 1996 hundreds of butterflies have flown freely in the butterfly paradise; terrariums show turtles, snakes, geckos and iguanas, and freshwater and marine aquariums round off the visit, extended since 2023 by the underwater world of the Neue Parkmitte. Aviaries and a monkey enclosure complete the ensemble, and the subtropical hall hosts safari-themed activities.

The Pflanzenschauhaus stands at the centre of the Luisenpark, in the Neue Parkmitte near the Kutzerweiher pond. Open whatever the weather, it draws many visitors on rainy days, and the adjoining café offers a break.

A visit combines easily with the rest of a 41-hectare park that has hosted two Federal Garden Shows, in 1975 and 2023: the walk-through aviary, the penguin enclosure and the Neue Parkmitte restaurant are only a few steps away. In winter the heated halls and the butterflies make for a sheltered outing.