The awards were held in London on 29 January and were attended by more than 300 people.
Massey won the Student Designer Commercial award for his design for the Cassel Hospital Ecotherapy Garden, a sanctuary for patients at Cassel in West London. It includes wild and landscaped areas, a playground, swimming pond, orchard, campsite and outdoor gym.
The award was presented by Andy Spetch, national topsoil manager for British Sugar TOPSOIL, which sponsored the award.
The winning design was acknowledged as "a very clean design that deals with the space with confidence, sensitive use of historical landscape and a sophisticated approach to the handling of space" by the judges, who included Sarah Eberle and Cleve West.
Massey also won best Student Designer Domestic for his garden at France Farm, which includes heathland planting, sunken outdoor kitchen and seating and a green-roofed garage.
He commented: "I am honoured to have my work singled out by designers such as Sarah Eberle and Cleve West whose opinions I respect enormously. And like all award winners I am grateful to the award sponsors without whose support there would be no awards."
Spetch said: "Tom is definitely someone to watch in the industry and British Sugar TOPSOIL is delighted to be associated with this exciting talent. We wish him every success in the future and congratulate him on his achievements at the SGD Awards."
British Sugar TOPSOIL is a strong supporter of the industry's awards schemes, sponsoring the Design & Build category in the BALI awards last year and planning the same for 2016.