Japanese Maples

Preface to the Fourth Edition
When J. D. Vertrees published Japanese Maples in 1978, he wanted to provide a comprehensive source of information on the culture, identification, and nomenclature of Japanese maple cultivars. He also intended to reduce confusion and bring stability to the naming of these cultivars. That his volume has become an invaluable reference book, the bible for maple growers and enthusiasts worldwide, is a measure of its success in achieving these objectives.
           
Since the last revision of this work in 2001, communications and the exchange of plants and materials between maple growers worldwide has mushroomed, resulting in almost a doubling of the Japanese maple cultivars now grown and collected by enthusiasts. Hence the time is appropriate for a larger, expanded 4th edition incorporating many of the newer cultivars and any changes in the growing techniques, taxonomy and nomenclature which have occurred in recent years—thus making it a more comprehensive up-to-date reference or encyclopedia of Japanese maples. And, as in the previous edition, to avoid endless repetition, cultivars of Acer palmatum are cited without a species name (for example, ‘Red Pygmy’), while cultivars of other species are always cited with the appropriate species name (for example, A. japonicum ‘Green Cascade’).
           
The introductory chapters remain essentially unchanged, although some topics are given more or less attention to reflect current trends. Chapter 2 places more emphasis on how to avoid and correct illegitimate cultivar names, chapter 3 has an expanded section on growing maples in containers, and chapter 4 moves away from commercial propagation methods toward those for garden and amateur enthusiasts.
           
Clearly, the main revision occurs in the plant description chapters with the inclusion of more than 100 additional cultivars which have proven their worth or become readily available since 2001. A total of some 420 A. palmatum cultivars are described in chapter 5, while 80 cultivars of other Japanese maple species, including those of A. japonicum, are described in chapter 6. Between them, chapters 5 and 6 cover the majority of the Japanese maples in cultivation. The remaining cultivars are briefly described or listed in appendices C and D. The descriptions of cultivars known in the late 1970s are primarily derived from specimens growing in the Maplewood collections, augmented by written material from early literature. The descriptions of the newer cultivars are based on specimens seen in various collections and nurseries, material received, and information provided by the originators or other knowledgeable collectors and growers. It has been difficult to describe adequately all the subtle differences occurring between cultivars.
           
The plant descriptions indicate the likely mature size of a plant grown under normal garden conditions and care. The detailed leaf measurements have been replaced with general terms for size—small, medium, large—which are more useful to most gardeners. Where it has been possible to accurately determine the meaning of Japanese cultivar names, that information has been added. Since most Japanese maples can grow in normal garden conditions in USDA hardiness zones 5 through 9, that information is omitted from the individual plant descriptions. Plants noted as being “tender” are only cold-hardy to zone 6. The color illustrations of the foliage were planned to assist in identification and not to present landscape situations. Where practical, an attempt has been made to include photographs which show the plant’s main attractive feature, whether spring or autumn color, winter stems, unusual foliage, or so forth.
           
The appendices have been updated. An additional appendix includes a list of plant suppliers who stock a good range of Japanese maples. The index, with nearly 2300 plant names, serves as the definitive list of all published Japanese cultivar names. Included in the index are all the Japanese maple cultivar names published in books, journals, and major catalogs of growers, including synonyms, and the names of cultivars no longer in cultivation—so that Japanese Maples will continue to be the foremost reference book for this wonderfully versatile collection of ornamental plants.
           
This revision could not have been accomplished without the cooperation, help, advice, and encouragement of numerous friends, colleagues, and correspondents. Conscientious attempts have been made to check the correctness of the cultivar names, origins, and descriptions acquired from my own knowledge and experience or from information and material received, to maintain the standards set by J. D. Vertrees. Whenever possible, samples from two or more different sources were compared. Hence, any errors or weaknesses that may have crept in are mine and mine alone.
           
It is hoped that these additions and changes will help to foster and strengthen J. D. Vertrees’ principal aim of introducing stability in the naming of Japanese maple cultivars while, at the same time, preserving his ideas, research, and unique style of writing.