Posted: 17/03/2013 at 18:47
Try working on diagonals, either one big one or divide it into 3 equal parts and then do a diagonam in each of those, bit like a patchwork quilt. Keep the planting palette simple with just a few plants repeated through the design.
Another soultion woul dbe to divide it into 3 and make a circle teh centre of each design using diffrent coloured gravels or grass. You could play with the circles and make them yin/yang with planting colours and contrasts to enhance them.