Winner Amanda Patton's garden design, The Traveller's Garden - with Bradstone, is being considered for the RHS Hampton Court Palace Flower Show in July.
If chosen, it will be built by a team of landscape contractors hand-picked from the winners of the APL Awards 2008.
Dorset-based Patton's design was inspired by Walter de la Mare's 1912 poem The Listeners, which tells the tale of a traveller who arrives at a moonlit door and waits for an answer. Patton's aim was to convey the eeriness of the poem by using contrasts of dark areas highlighted with very pale colour.
APL chairman James Steele-Sargent said: "I'm delighted that Amanda's entry was chosen. Her design really stood out and it would make for a beautiful garden at Hampton Court.
"Through Amanda's garden we hope to highlight the benefits of working with professional designers and landscapers."