He obtained his early education at the Cape Town Technikon with a National Diploma in horticulture,[1][3] and joined the Kirstenbosch National Botanical Garden, Cape Town, South Africa in 1978, where he came under the influence of Winsome Fanny Barker (1907–1994), then curator of the Compton Herbarium at Kirstenbosch and a Lachenalia specialist.
[6] He is considered an authority on the cultivation, conservation, propagation and biology of bulbs of the Cape region, and the leading expert on the genus Lachenalia.
As well as identifying a number of South African plants,[9] he has also bred cultivars such as Clivia miniata 'Kirstenbosch Splendour', which illustrates the cover of the Kirstenbosch centenary book (2013).
[13][14] He is the author of numerous books, including several titles in the Kirstenbosch Gardening Series, scientific papers and popular articles on South African bulbous plants.
[8][9][5] In 1989, he was awarded the Recht Malan Prize for non-fiction (1989) from the Nasionale Boekhandel for his Bulbous plants of southern Africa [15] and in 2001 he was the recipient of the International Bulb Society's Herbert Medal.