Book Reviews: Horticultural

The Gardener's Guide to Growing Hostas is aimed principally at amateur gardeners and, to a lesser extent, at professional horticulturists. Chapters on cultivation, propagation, and breeding provide the detailed information necessary to grow and maintain Hostas in virtually all temperate climates. The horticultural varieties appear to be less well-suited for tropical or subtropical gardens, although the brief summary of the state of Hosta horticulture in Australia (1/2 page) illustrates that they can be grown in the antipodal heat as well. The section on garden uses presents a variety of well-conceived plantings that can show off the different foliage types to their best advantage.

Chapters on 'people and their plants', growing Hostas for exhibition (by Richard Ford), and chapters on regional collections and cultivation (Japan, by William Burto; North America, by Warren Pollack; Europe, by Ullrich Fisher; Australasia, by Gordon Collier) provide the reader with an entree into the history of the development of respected horticultural varieties and the current world of Hosta fanciers. Diana Grenfell, as well as all the chapter contributors, are leading members of Hosta societies in their home countries and internationally, and they convey well the excitement that must transpire in gatherings of Hosta aficionados.

The bulk of the book is a comprehensive listing and description of all the varieties of Hosta that are currently in cultivation. Most varieties are illustrated with photographs, either in this section, or elsewhere throughout the book. This section, along with the appendices listing names and addresses of growers and merchants of Hostas, locations and visiting hours of reference collections and notable Hosta gardens, and the three principal Hosta societies (Britain, USA, and the Netherlands) would enable anyone to begin, maintain, or expand their collection of Hostas.

Systematics and nomenclature of Hosta is now reasonably stable. Piers Trehane's short chapter on conventions for naming new Hosta cultivars lays out the current procedures for registering new varieties according to the 1995 edition of the International Code of Nomenclature for Cultivated Plants. Currently, all cultivars are maintained and registered through the International Registration Authority for Hosta based at the University of Minnesota Landscape Arboretum. 'Good' species and cultivars of Hosta were distinguished by W. George Schmid in his 1991 book, The Genus Hosta, and Grenfell's chapter on the history, habitat, and classification of the genus follows Schmid's division of Hosta into three subgenera (Hosta, Bryocles, Giboshi) based principally on geographical distribution. Interestingly (at least to this horticultural novice), while species are distinguished (as expected) principally on the basis of floral characters, Hostas are valued in gardens for its striking foliage, and virtually every new cultivar is bred for unique leaf characteristics and overall plant shape.

Overall, I was very pleased with this book. It provides adequate scientific background (and sufficient references) to lead any botanist down the garden path into the technical literature on the genus. In addition, that path is lined with beautiful photographs and laid out with enough excitement to convince even the most amateur gardener or budding landscaper to plant some Hostas. - Aaron M. Ellison, Dept. of Biological Sciences Mount Holyoke College, South Hadley, Massachusetts

Ornamental conifers for Australian gardens. R.J. Rowell. 1996. ISBN 0-86840-239-7 (hardcover US $44.95) xxviii + 167pp., 107 color photos on 32 unnumbered plates. University of New South Wales Press (Distributed by International Specialized Book Services, Inc., 5804 N. E. Hassalo Street, Portland, OR 97213-3644 - Here is a nice presentation of the cultivated conifers of Australia, the majority of which are imports from the northern hemisphere. It contains generally good non-technical descriptions of the approximately 40 genera, 150+ species, and 350+ additional cultivars included, with useful and interesting notes on native habitat, cultivation, landscape impact, and commercial use, accompanied by very nice silhouettes of habit in youth and age and excellent color photographs of about a third of the species in the book, all by the author.

Two elements are of particular note for North Americans with gardening interests. First, the book includes descriptions of many of the less familiar cultivats that have emerged from the thriving horticultural industry in Australia. Second, there is a full discussion of Australian cultivation zones, based on temperature and precipitation, that reaffirms how little of Australia is climatically similar to any part of North America. This carries implications, of course, for cultivating Australian plants here and vice versa. Perhaps this partly underlies an occasional schizophrenia in the book that contrasts phrases like "...several of the species [of Australian Callitris] outclass many overrated, introduced species "with"...Monterey Pine ... has emerged a clear winner as the most suitable selection for the tablelands region."

Southern conifers are surprisingly underrepresented in this book. Rowell's statement that "the Northern Hemisphere, with its greater land-to-sea ratio than that of the Southern Hemisphere, is similarly superior in native conifers..."better reflects their treatment here than the fact that about half of the world's 70 genera of conifers are southern. Omamental Conifers includes 28 northern genera versus only 18 southern ones (some of which are buried as synonyms), even omitting some Australian genera, like Diselma, Microcachrys, Microstrobos, and the celebrated Wollemia (presumably too recently described for inclusion). Pinus and Podocarpus (even when restricted to just sect. "Eupodocarpus" of Gray and Buchholz) each have about 100 species, however in this book there are about 30 pines and only 10 podocarps (in the broad sense).