This is book is quite simply superb. I bought it yesterday and finished it in one sitting by bedtime. Jake writes with authority, having learned his skills in a nursery in Japan, and delivers a fascinating yet practical account of the importance of the pruned landscape in Japanese gardens. Niwaki literally means "garden tree" and is, in effect, the garden-planted equivalent of bonsai. Japanese terms are helpfully explained and it was intriguing to read that the term "cloud pruning" is really no more than western marketing-speak: there IS no Japanese equivalent! Similarly, the expensive pruned Ilex crenata bushes that we see down the garden centre with a several thousand pound price tag are infrequently used in Japan (there are more interesting plants to use) but essentially designed for the export market (shades of all that Imari porcelain made in the 19th c for the European market, I think). The book is lavishly illustrated with many high-quality colour photos and lots of drawings to show how to undertake the various pruning techniques. There are sections on the evolution of niwaki, the distinctions between formal garden and pruning in a temple garden versus a smaller domestic garden, a whole chapter on pruning pines, and chapters on pruning deciduous trees such as acers and evergreens such as cammelias. What I particularly like is Jake's philosophy; few people in the UK are going to create a true Japanese garden, so better to adopt and adapt Japanese elements to our garden settings and the range of plants that grow best in our gardens. For a start, our gardens may already be full of suitable plants of Japanese origins such as azaleas, rhodos, acers etc. All they need is a sympathetic clipping. Also, as he points out, we already have a great tradition of shaping trees in the forms of our fruit trees and topiary, so it's a small step to developing a Japanese pruning approach to plants such as box or yew in our gardens.
A good companion for this book would be "Garden Plants of Japan" by Ran Levy-Yamamori and Gerard Taaffe. This 400+ page encyclopedia of trees, shrubs, grasses and climbers has little on Niwaki techinique, but is well illustrated and describes which species or cultivars are suitable for pruning, hardiness etc.