He was elected a Fellow of the Royal Society in June 1874. He was the author of scientific works including The Quinology of the East Indian Plantations (1869–1876), religious works including a commentary on the book of Hebrews and histories including The Island Of The Saints, about the Reformation in Ireland. The family lived at Lord"s Meade, Lordship Lane, Tottenham.
Howard died in Edmonton, London at the age of 76 and is buried in Tottenham Cemetery.
The genus Howardia of the Rubiaceae was dedicated to him.