Started his professional career as an industrial chemist. He had a keen interest in the propagation and cultivation of Australian native plants and was involved in the establishment of the Society for Growing Australian Plants (SGAP) and the setting up of the Kuringai Wildflower Garden in the late 1950s and early 1960s. Appointed Curator of the Canberra Botanic Gardens (now Australian National Botanic Gardens) in 1967. Landscaped the Australian Pavilion at Expo'70 in Japan. Undertook extensive field collecting 1967-81. Retired from the Australian National Botanic Gardens in 1981 and moved to Coffs Harbour, NSW, to undertake private horticultural consulting. He has also designed botanic gardens in Coffs Harbour, Mildura and Tamworth and a nature park at Port Macquarie.
Made a Member of the Order of Australia in 1983 for services to horticulture.
Published a landmark series of books, in collaboration with Murray Fagg, on the horticulture and general botany of the Australian flora, including Australian Native Plants - Propagation, cultivation and use in landscaping (1978, 1983, 1988, 1996, 2003); Banksias, Waratahs and Grevilleas (1989) and Bottlebrushes, Paperbarks and Tea Trees (1993).