Chichester College won best in show at the third annual Ideal Young Gardeners of the Year competition. Capel Manor College also won gold, Bridgwater silver gilt, Askham Bryan and Writtle silver and Shuttleworth bronze for their sustainable urban gardens.
The Chichester garden, called "Up Wood", incorporates up-turned tree stumps and specimen trees such as Prunus avium 'Plena', Betula utulis var. jacquemontii and Amelanchier lamarckii.
Chichester College horticulture lecturer Mark Howard said the competition could boost interest in horticultural courses at the college. "More shows like this will be good publicity for the college," he added.
Competition organiser David Domoney said: "Everything that offers a touch of glamour to the industry is positive. The general view is of people in high-vis jackets, which is part of it, but it is also about exciting and energetic tasks and the chance to run your own business."