Drainage

This garden on clay was developed in the 1920s, the owner writing a book about the experience. It turned out to be largely a catalogue of errors, and in the final chapter of the book he admits that he should have drained the garden first! That task fell to me some 50 years later - you can clearly see the water streaming from the ground, the result being spectacular.
A cautionary tale - adequate drainage is a vital ingredient for a successful garden!