As a botanist, Smuts collected plants extensively over southern Africa. He went on several botanical expeditions in the 1920s and 1930s with John Hutchinson, former botanist-in-charge of the African section of the Herbarium of the Royal Botanic Gardens and taxonomist of note. Smuts was a keen mountaineer and supporter of mountaineering. One of his favourite rambles was up Table Mountain along a route now known as Smuts' Track. In February 1923 he unveiled a memorial to members of the Mountain Club who had been killed in World War I.