Hutchinson, who was educated at the village school in Wark-on-Tyne where he was born, began work in 1900 under his father, the head gardener on a large estate. In 1904 he was appointed to a junior post at the Royal Botanic Gardens, Kew, where he remained for the rest of his career. Starting as an assistant in the herbarium he was in charge of the Africa section from 1919 until 1936 when he became keeper of the Museum of Economic Botany, a post he occupied until his retirement in 1948.

Hutchinson's most significant work was his Families of Flowering Plants (2 vols. 1926–34; 2nd edition 1959), which contains details of 342 dicotyledon and 168 monocotyledon families. Hutchinson drew most of the illustrations for this work himself. In it he concentrated on the different plant families that various workers had considered the most primitive. He concluded that bisexual flowers with free petals, sepals, etc., as seen in the magnolia and buttercup families, are more ancient than the generally unisexual catkinlike flowers found in the nettle and beech families, which lack these parts. This conclusion supported the classification of George Bentham and Joseph Hooker and added weight to arguments against the system of Adolf Engler. Furthermore Hutchinson stated that families with apparently more simple flowers are in fact more advanced, and have evolved by reduction from more complex structures; that is, the families show retrograde evolution. In this, the now generally accepted view, Hutchinson was developing the earlier ideas of the German botanist, Alexander Braun.

An enormously prolific and industrious worker Hutchinson also published, with John Dalziel, the standard work, Flora of West Tropical Africa (1927–36) and at the time of his death was engaged in a revision of the Genera Plantarum (Genera of Plants) of Bentham and Hooker.