In 1790, he began the first of several huge projects: a 36-volume work, English Botany that was published over the next 23 years, contained 2,592 hand-coloured engravings and became known as "Sowerby's Botany". An enormous number of plants were to receive their first formal publication within this work, but the authority for these came from the initially unattributed text written by James Edward Smith. The work was continued by his son, James de Carle Sowerby who published a further set of 204 plates, mostly uncoloured until the end of the first edition in 1835. Further plates were added by other hands up to 1865 ending with plate number 2,999.