In 1708 he left with his brother-in-law Peter Tillemans to England to work for a picture dealer named Turner for whom they made copies of Old Master paintings.
[3] Casteels became an active participant in London's artistic community, subscribing to the Kneller Academy of Painting and Drawing in 1711 and becoming a member of the Rose and Crown Club.
He developed a successful practice as a painter of flowers and exotic birds that chiefly served a decorative purpose as overdoors and chimney-pieces.
His customers included James Stanley, 10th Earl of Derby who bought imported art as well as original work of Casteels.
[4] In May 1735 he retired from painting and spent his last fourteen years working for a calico manufacturer as a residential artist, first at Martin Abbey near Tooting, Surrey, and later, briefly, in Richmond, London.
[7] As he spent most of his active career in England, a large portion of his work is in public and private collections in the UK.
[9] The 12 paintings by Casteels were engraved by Henry Fletcher and published by Robert Furber, a British horticulturist, under the title the Twelve Months of Flowers in 1730.
[16] The complete set of the 12 original paintings, which Casteels made for the series, were sold by Christie's on 25 May 2005 in New York as lot 1529.