He went to Eastbourne College where he attained the Higher School Certificate in Physics and Double Maths.
He was commissioned as a 2nd Lieutenant when called up for National Service and posted to 110 Army Troops Squadron in Austria.
He later studied botany at Norwood College for a year and started his interest in the identification of grasses.
This was followed by four years working as an ecologist at the Federal Agricultural Research Station at Ibadan, Nigeria.
Derek Clayton married Lucille Hicks in 1953 at Hampstead; they had a son and two daughters.