A Comprehensive Guide to Cultivars and Species



Review of Encyclopedia of Conifers published in Conifer Quarterly, American Conifer Society


A review of RHS Encyclopedia of Conifers is published in Conifer Quarterly, written by Mr Tom Cox, former national president of the American Conifer Society.

Tom Cox in his review states that "... unquestionably this is the magnum opus of all books ever written on conifer cultivars. No other work comes close!

Seven years in the making, this two volume (1,500 pages) set is beautifully illustrated with over 5,000 high quality photographs. As a reference book for conifer cultivars, the photographs are accurate and while the actual plant may slightly differ based on growing conditions, they provide the reader with a good idea of what the plant might look like in the landscape. It is refreshing to see large photos instead of the typical thumbnail shot that is lacking in detail. Also, many pages are devoted to a high resolution, full page image of a single specimen. No other book offers this. Covering about 8,000 cultivars, and all of the world`s 615 conifer species (this number varies based on the taxonomist), plus their subspecies and varieties, this is a herculean effort.

While the rather brief description of each cultivar is about the same as one would typically find in a good nursery catalog, what makes this work special is the vast number of plants that they cover in this one work. I am astounded at the sheer number of hours in research this must have required. The authors mention the synonyms for numerous cultivars which can be helpful where one is attempting straighten out their database as well as labeling. This is well researched and they provide some interesting history. For cultivars they also include the discoverer or originator, date and country of origin. There is a botanical consistency throughout the book and the authors have closely adhered to the International Code of Nomenclature for Cultivated Plants (ICNCP).

As a reference for most of the world`s recognized cultivars it is without peer but as a general conifer reference, it misses the mark. This is not a criticism as such, since this work serves to augment previous books by authors such as Farjon, Eckenwalder, Debreczy and Racz who did not address cultivated varieties. From a taxonomic standpoint, the authors follow Farjon in their treatment of the 615 species they cover. Their inclusion of species also helps the reader attain a better understanding of lineage. Understandably, temperate conifers receive more detailed coverage, but an overview of tropical conifers is also offered.

My only criticism is the same as that with all European authors and those from other regions outside the southeastern U.S., their knowledge of growing conditions in the region appears non-existent and for some reason they appear reluctant to reach out for data. No pictures appear from the southeast region and no principle conifer collectors, nurseries or arboreta are mentioned in their "List of Originators." This is further manifest in the absence of cultivars in their book with a southern origin such as Cryptomeria japonica "Komodo Dragon", Tarheel Blue", "Chapel View" and "Radicans" -- four excellent selections of Japanese cedar. Also, in a number of instances, the authors are incorrect in their zone hardiness for various species that have performed well in Zone 7 and 8 where they rate them as Zone 9. These predictions are often based purely on the native habitat and also fail to take into account the effect of summer heat on hardening of wood. The potential downside to these generalizations is that gardeners may not be tempted to try something that is rated as tender.

With noted extremely minor exceptions, I like this book a lot and highly recommend it. It is my "go to" source for information on cultivars and the book of its type that I most value. The format is easy to use with each genus being listed alphabetically, followed by its various species and then cultivars. No book on conifers that I have ever come across has this many pictures. Many were photographed in summer and winter to show color and texture changes through the seasons. While some of the cultivars may currently not be attainable in the U.S., this is a great book to peruse on those cold winter days when all we want to do is sit by a fire."

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