He has an honours degree in botany from the University College of Wales, Aberystwyth, a master's degree and doctorate from the University of Melbourne (in phycology) and a technical certificate in gardening and turf maintenance from Oakleigh Technical College, Melbourne.
He is currently horticultural botanist at the Royal Botanic Gardens Melbourne where he works in the Plant Identification Service, contributing locally and internationally to the study of cultivated plant taxonomy.
He has also written books on topics including landscape conservation, elms and silver foliage plants.
He is the co-author of the book Sustainable Gardens and an international third edition of the booklet Plant Names.
[3] He has contributed to the Australian native floras of Victoria, New South Wales and South Australia, and was for several years chairman of the Australian Cultivar Registration Authority.