Garradd was born in Australia and lived his early life in Sydney, Canberra, Oberon, and Tamworth. Astronomy has been an interest since his childhood, and he has built many telescopes himself, starting with a 20 cm (8") f/7 Newtonian while still in high school, graduating to making mirrors up to 46cm (18″) diameter and mounts up to the fork mount for the 46cm f/5.4 Newtonian, and German equatorial mounted 25cm (10") f/4.1 that he used for observing NEOs and comets. His initial profession was as an accountant, but he left that in 1984 to pursue astronomy and photography full-time. He lives with his wife Hether, off the power grid, using solar and wind power. He is a photographer, mountain bike rider, and solar- and wind-power enthusiast.