The author's own garden is in North Wales, but she is familiar with Scottish and Cornish gardens and growing conditions and is fully cognizant of the findings of Dr. Henry Tod, leading authority. There are more extensive- and intensive- books on the subject, but this relatively small book covers a great deal competently. Against an historical background, natural history, cultivation and propagation, she proceeds to weigh the many facets of the genus, its varieties and their uses, the association with other plants in the garden scheme, the most problem of soil-preferences and corrections, the places where they should be grown -- and how. Brief attention is given to hybridizing and to treatment of diseases and pests; presumably, this information is more extensively treated elsewhere. Part II is a succession of listings, rhododendrons and azaleas for the garden, hybrids, species, and a final brief rundown of nurseries. While the material pertains to the British Isles, American growers can make their adjustments in seasonal differences, or local conditions, etc.