Lucy Diecks taught art at Atherton High School in Louisville, Kentucky, after studying at the Corcoran Art School in Washington, D.C. Like several Louisville painters of her generation, she was involved in the art scene in Provincetown, Massachusetts, and also painted in the Southwest. According to her niece, Barbara Brooks, Diecks "put down her brushes in the 1960s and never painted again." She didn't know why.

Diecks was represented in the ground-breaking exhibition Kentucky Women Artists: 1850-2000 in 2001-2002.