RCN soon established his business in Woodbridge, moving with Maud into the old Georgian House on the nursery.

As RCN developed the nursery, his interests widened, holding membership of the Royal Horticultural Society (RHS) Flower Show Committee for 30 years, of the Linnaean Society and of the Council of the Roads Beautifying Association (one of the earliest associations concerned with the environment). In 1912 he was appointed a JP. He served as a member of the Woodbridge Urban District Council for 33 consecutive years, being elected chairman in 1937.

RCN had an intense love of the countryside; as an expert on trees, his counsel and help were especially valued by the Suffolk Preservation Society, on whose Executive Council he served. In 1934, he donated the 4 acres of Kyson Hill to the National Trust - their first donation in Suffolk. This is a lovely stretch of hillside, with wide views of the River Deben. The Notcutt family have retained the link with the National Trust and of Kyson Hill, celebrating in November 2009 the 75th anniversary of its donation with the planting of an English Cherry by Charles Notcutt with the 3rd, 4th and 5th generation descended from RCN looking on.

RCN became particularly interested in trees and shrubs, amassing a large collection. He published "Flowering Trees and Shrubs: a handbook for gardeners" in 1926.

His management style reflected the times. The office manager was Ernest Bilney, and the nursery manager was Edward Thatcher. Each loathed the other, and would take every opportunity to tell RCN of the other's failings, so although RCN was regularly away from the nursery, he knew exactly what was going on.

In 1938, disaster struck. In January of that year RCN died of a heart attack. Like many first generation businessmen, he had not thought to the future, and had not trained Tom to succeed him. Although Tom dealt with all the sales correspondence in the office, and conducted customers around the nursery, he had not been involved in the day to day operation of the nursery or in controlling the indomitable Bilney and Thatcher. Suddenly he was expected to achieve all this, and to report on each day's activities to his mother, Maud. Unfortunately, it was not to be and Tom died that September.