In 1957, Dawson was appointed to the faculty of the Department of Botany at Victoria University College (from 1962 known as
Victoria University of Wellington), and remained there until his retirement in 1988, having risen to the rank of associate professor. He served as head of the Botany Department between 1984 and 1987. and he also studied New Caledonian flora from the family
Myrtaceae. Dawson's book, ''New Zealand's Native Trees'', co-written with Rob Lucas, was named "Book of the Year" at the
2012 New Zealand Post Book Awards. ==Death==