And now the informal pool. You have probably noticed that it is never quite successful to have any form of margin between the water and the turf in places where the grass runs right up to the pool; unless the grass rolls right into the water, and so often the reason that the margin is there at all is that there is a four-inch wall of concrete that is rather puzzling. If the top of this wall is bevelled back towards the lawn instead of being finished level, the grass will grow right to the water's edge. Big, flat boulders placed with restraint and artistry can be as delightful, as a row of stones can be hideous for the parts where the shrub border butts on to the pool. We may learn so much from the Japanese in these matters, for surely no other people know the art of placing boulders as they do.