The 154-year-old Singapore Botanic Gardens on Friday unveiled plans for a heritage museum and separate gallery for green exhibits.

The 240 sq m museum will contain artifacts such as the Gardens' oldest specimens and botanical artworks. The actual artifacts in the museum may be digital versions if things are particularly fragile or rare. The museum will be housed at Holttum Hall near the Gardens' Tanglin entrance. Built in 1921, the hall was the office and laboratory of Gardens' director Eric Holttum, who pioneered test-tube orchid breeding techniques.

In addition to the museum, a 314 sq m solar-powered gallery, the size of three to four HDB flats, will be built of concrete made from the hemp plant by developer City Developments Limited (CDL). Sited on Holttum Hall's lawn. it will first showcase a half-century of "greening" Singapore.

Together, the new additions will cost about $2 million in cash and kind from CDL, and are expected to be ready by the end of November. They will help the iconic gardens in its bid to be Singapore's first World Heritage Site by educating visitors about its history, said director Nigel Taylor.