Wardle had his work exhibited at the Royal Academy aged just sixteen. He had a life long interest in drawing animals. His depiction of a lion produced for the Parliamentry Recruiting Committee during the first world war remains an iconic image.
Elected to the Pastel Society in 1911, the Royal Institute of Painters in Water Colours in 1922, he exhibited widely. His work was reproduced on postcards, calenders and even chocolate boxes. His depiction of a Fox Terrier in the modern form is probably the earliest known and still hangs at The Kennel Club.