Outside of Doctor Who, he is perhaps best known for his role in the British comedy television series The Goodies with Tim Brooke-Taylor and Bill Oddie. The show ran from 1970-1980 on the BBC and 1980-1982 on ATV. When the BBC cancelled the show the budget reportedly went to making the TV series The Hitchhiker's Guide to the Galaxy. After The Goodies finished, the trio created, wrote and provided the voices for the kids' cartoon series Bananaman in the mid 1980s.
The trio had previously worked together with the likes of John Cleese on the BBC Radio programme I'm Sorry I'll Read that Again from the mid 1960s to the early 1970s. When that programme ended, Garden and Brooke-Taylor created the spin-off radio show I'm Sorry I Haven't a Clue. Starting in 1972, the self-styled "antidote to panel games" continues to this day.