The judges - including Hillier Landscapes managing director Richard Barnard, RG Landscapes director Roger Gladwell and sponsor Bradstone's head of marketing Ian Wright - have chosen the winners in 12 categories.
A new category introduced for the 2009 awards - which will be held on 11 February at Sketchley Grange Hotel, in Leicestershire - is Young Landscaper of the Year.
Other categories include: Front Garden; Overall Design and Build; Commercial Garden; Garden Maintenance; and Supreme Winner.
APL vice-chairman and chairman of judges Mark Gregory said: "We are extremely impressed with the size of contracts some of our members are tackling and the quality they are achieving."
He added: "Choosing the best young achiever was by far the hardest decision, as the candidates were all so good."
Garden designer, author and TV presenter Andy Sturgeon will give a motivational talk after the awards presentation.