Irises can cause obsessions with some gardeners, causing them to search high and low around the country, always on the hunt for new varieties and colour-ways. But they are not new plants. They have been around for centuries causing rivalry between the Ancient Greeks and Egyptians who both idolised their diverse form. Even today they are highly prized amongst connoisseurs of fine plants and the huge hybridisation programmes are testament to this. Varieties of iris can be found in flower virtually every month of the year - the winter-flowering Iris unguicularis, the spring flowering Juno iris, the summer-flowering bearded iris and the autumnal Iris foetidissima. Even out of flower their foliage either dies neatly away or remains as a statuesque reminder of their stateliness. Variegation can add to this interest but in some eyes detracts from the flowers when blooming. And situation-wise there are iris amenable to nearly all - the moisture loving Iris sibirica, the baked-earth lovers Iris bucharica, the shade-loving Pacific hybrids. And their uses within beds and borders are almost infinite. Authors Sidney Linnegar and Jennifer Hewitt, both of the British Iris Society, share their immense knowledge of these diverse plants clearly explaining the various technical terms involved and advising on cultivation and propagation, all accompanied by lavish colour photographs and pen and ink drawings of horticultural techniques. Part of the RHS Wisley handbook series, this is a comprehensive and concise look at iris, fully illustrated and clearly written. Aimed at both the amateur and professional grower, this is an invaluable addition to any serious horticulturalist's bookshelf. - Lucy Watson