GCA chief executive Gillie Westwood said: "Our congratulations go to Castle Gardens for coming first in the garden centre category and to Barton Grange Garden Centre for topping the destination garden centre group.
"The garden centres are judged on the innovation, inspiration and excitement created from the way their Christmas products are displayed. The range of products available, accessibility, how easy it is for customers to find and select products and ‘wow factor’ are also taken into consideration.
"I’d like to thank everyone who took the time to enter the competition. Once again it was a great success and my congratulations go to the winners and runners up."
Second place in the garden centre category went to Sunshine Garden Centre in London and third place to All-in-One in Middleton, Manchester.
In the destination garden centre category, Endsleigh Garden & Leisure in Ivybridge, Devon, came second and Perrywood Garden Centre & Nurseries in Essex, came third.
Finalist judge Liz Hutson said: "This is the second year running that I had the privilege of judging the GCA Christmas display competition and I was overwhelmed by the standard of entries. It was really tough to judge because all the garden centres had excelled in several areas.
"I was particularly interested to see the same garden centres I saw last year because they had all improved tremendously.
"I will be giving a presentation at the GCA annual conference on Tuesday, January 24 to share the great ideas that the finalists had with other members of the association."
The GCA 2012 Conference takes place from January 23 until 25 at the Crowne Plaza Heythrop Park near Chipping Norton, Oxfordshire.