Minimizing water-use is already of major concern in many parts of the world and will be an increasing influence on how we irrigate our gardens in the future. The author, inspired by a technique invented 2000 years ago by celebrated Chinese agriculturalist Fan Shengzhi, has produced a handyman’s guide to inventive, low-cost, super-efficient watering systems.
Burying an unglazed clay pot (or olla) in the soil provides controlled irrigation to nearby plants by capillary flow. The system has been used successfully for growing a wide range of perennial plants, including citrus and other fruit trees, all over the world. The author has used the technique successfully in desert restoration projects in California. Even if you don’t have a desert to restore, the system can be easily adapted for watering potted plant containers or providing irrigation for large vegetables such as courgettes or melons.
The book goes on to explore other economical and effective systems. Porous capsules are a variation on the olla system, and are of particular use for plant containers. Deep pipe irrigation uses a vertical pipe to deliver water to deeper soil where it is safe from evaporation. Cotton or nylon wicks may be used to draw water from a container and deliver it into the soil (capillary matting is a variation of this technique). Porous hose is already a familiar concept to most gardeners in dry areas and although it has the drawback of emitting water along the whole of its length, it is the most commercially available of the systems described. Buried porous clay or concrete pipes use the same technique as ollas, while tree-shelters (or grow-tubes) are a simple plastic tube positioned round a plant, into which water is then poured by hand.
The author then gives advice about water-wise gardening in general and about harvesting rainwater in your own garden. It should be mentioned that the book is written for an American rather than a European audience and assumes an almost complete lack of knowledge about water-wise gardening.
The most appealing thing about this liberally illustrated little manual is that it provides detailed instructions for do-it-yourself versions of all these ingenious systems, which will delight the heart of the home-handyman. Clay pots apart, the systems described are somewhat functional from the aesthetic point of view, and are probably more appropriate for small-scale agriculture or vegetable production than for ornamental gardens. Nevertheless, the basic ideas are certain to inspire the imagination.
Review by Michèle Bailey - Mediterranean Gardening France