RHS Encyclopedia of Conifers: A Comprehensive Guide to Cultivars and Species is a joint effort between the society and Kingsblue Publishing, detailing conifer cultivars and species. It was written by leading conifer experts Aris Auders and Derek Spicer.
RHS editor of specialist publications Mike Grant said: "There are now thousands of conifer cultivars available so this complete reference book is a much needed guide to this fascinating group of plants."
The two-volume doorstop includes over 5,000 photos while a 1500-page encyclopedia features 8,000 cultivars and all 615 conifer species with their subspecies and varieties - more than any other illustrated book.
Cultivar information was compiled by cross-referencing the RHS International Conifer Register, including as yet unpublished data. The pages include descriptions, finder or originator, date and country of origin, and synonyms.
"Particularly useful is a guide to size after 10 years for the majority of cultivars," said Grant. "The species descriptions follow the most recent botanical classification of Farjon (2010)."
The book was rounded off with an appendix listing all the conifer collectors, nurseries, arboreta and individuals responsible for introducing new cultivars over the last three centuries.
Aris Auders, a conifer collector and photographer from Latvia, and Derek Spicer, chairman of the British Conifer Society, have been working on the book for seven years.