Garnet Wolseley first sold a painting, Rough Seas, at Newlyn Art Gallery in 1908 and in 1909 he exhibited A Fairy Story and A Silver Sea. He served on the main committee of the Newlyn Society of Artists, and the hanging committee of the Gallery from 1911 to 1913, when Charles Walter SIMPSON undertook to replace him on the Management Committee.

Penlee House has his painting of St Michael's Mount (oil on canvas), gifted by the Friends and the Simon Levy Charitable Trust in 2001. Wolseley features in back profile with Laura KNIGHT and Florence CARTER-WOOD, modelling as a butler in the painting by Harold KNIGHT, Afternoon Tea (1910). The setting was Wolseley's drawing room in Newlyn. Laura Knight describes him taking part in wild but sparse attire at one of Phyllis Maureen GOTCH's extravagant parties. He worked from Sandy-Cove Studio, Newlyn, often painting in the Lamorna Valley nearby, until 1913.