Pflanzenschauhäuser (Plant Show Houses), Rombergpark Botanical Garden

The Rombergpark grew out of the estate of the von Romberg family, whose lime avenue was planted in 1822. In 1927 Dortmund's botanical garden left its former site on Beurhausstraße in the city centre and moved here. In the early 1950s Konrad Glocker drew up a development plan for the park, and the rose garden and the show glasshouses were created under him.

The first phase of the glasshouses opened in 1958 at the southern end of the garden. An overwintering house for subtropical and Mediterranean container plants, already planned in 1959, is still among the projects. In 2006 the whole botanical garden was entered on the city's list of monuments, including the four glasshouses and the Café Orchidee. The city renovated them in 2007, and for their fiftieth anniversary a grove of 35 Wollemi pines was planted in the central Coal Age flora house.

In 2016 the Bonn botanical gardens donated a titan arum, named David, which flowered on 17 August 2018; its 20-30 kg tuber was stolen in October 2025. A cooperation agreement was signed in September 2018 with the botanical gardens of the Seychelles. The Coal Age flora house was redesigned in September 2025, and a plan for 2027 foresees three new glasshouses, devoted to Tasmania, the Seychelles and New Caledonia, which would almost double the exhibition area.

The four show houses form a group of about 1,100 m² under glass at the southern end of the garden, in the Krüssmann Arboretum, at Mergelteichstraße 40. The Café Orchidee stands centrally in front of the buildings and is listed along with them. The sources consulted do not name the architect or describe the structure.

Each house corresponds to a climate: the warm house, now the tropical house; the succulent house, now called the cactus or desert house; the cool house, renamed the Tasmania house; and the fern house, which has become the Coal Age flora house. The Tasmania house has been fitted out to let visitors linger, with accessible toilets and an area with tables and chairs for talks and exhibitions. The extension planned for 2027 would add three houses to this 1950s ensemble.

The cactus house brings together cacti and succulents, including agaves; every May it hosts the Dortmund Cactus Days, organised with the city's cactus enthusiasts, as well as spring exhibitions from late December. The Coal Age flora house presents ferns, horsetails and clubmosses, relics of the Carboniferous flora, along with bananas that thrive in its climate.

The Tasmania house gathers plants from the South Pacific such as eucalyptus, Corokia, a shrub with zigzag branches, and podocarps. The tropical house shelters orchids, bromeliads, a cacao tree, palms, bamboo and the titan arum; an iguana lives there, while the water turtles of earlier years are gone. An orchid show is held there from late January to late March.

The glasshouses stand at the southern end of the Rombergpark botanical garden, on the Mergelteichstraße side; the Café Orchidee in front of them offers a break. A visit combines well with the garden's outdoor collections, especially the Krüssmann Arboretum and the rose garden created at the same time as the glasshouses.

Late winter is a good time to come, with the orchid show from late January to late March, as is May, when the Cactus Days take place. Dortmund Zoo, next to the park, can round off the day.