Thanks for your reply Mondaychild! I had so many conflicting amounts of cement to sand mixtures and was told by a builder to do 3 sand to 1 cement plus a drop of washing up liquid to the water. Also, dig a trench about a foot deap and fill with this mix and chips! Then use a saw and shape the blocks to suit the area. Got the impression he wanted to do the job, and was putting me off on purpose! Determind to do this job myself, my garden is 120ft long and want to do 4 of these planters starting at the corners making a sort of triangle in the middle. Will ofcourse have to wait for our weather in Scotland to warm up! Thanks again Impatience

for three foot wall put a block on side for foundation, on some crushed rubble about 3 inch deep. Mortar can be one cement to eight sand, and this will do for the render. Curves are difficult, try staggered short straights