Stan's superstore has agreed to sponsor the competition.
All the pupils from both schools have been invited to take part and the winners will be chosen from seven finalists from each school.
Judging will take place at 2.45pm and Steve and Linda from Stan’s will be on hand to help with deliberation.
The boxes will be displayed in the President’s tea tent .Fete organisers say they are very grateful to the staff and parents at both schools for their cooperation and are pleased that, along with the management at Stan’s, they are able to encourage local youngsters to take an interest in gardening and the environment.
The fete, starting at 2pm with free admission, will have all the usual attractions, stalls, refreshments and activities for the children.
The main arena attraction will once again be the Cwmwd Iâl re-enactors but fete organisers say this year’s performance will be even bigger and more spectacular than last year.