Hart was a regular face on the BBC children's programme "Blue Peter" in the 1950s and presented a number of programmes in 1959. Richard Marson's book "Blue Peter: Inside the Archives" lists Hart as a presenter in November 1959 but he is not officially listed as a host. As well as demonstrating small-scale projects (the type that viewers might be able to do), Hart also created large-scale artworks on the TV studio floor, and even used beaches and other open spaces as 'canvases'.