established, mature, and storm-damaged trees, Dirr’s Encyclopedia of Trees & . Book Reviews provides detailed instructions for pruning spe- Michael A. Dirr. 2011. Timber Press, cific trees that include crape myrtles, conifers, Portland, OR. 951 p., incl. indices (botan- palms, and cycads, and offers techniques ical and common names). $79.95 hard-

rd for pruning shrubs. Chapter 16, ‘‘Root Prun- cover. ISBN-978-0-88192-901-0. An Illustrated Guide to Pruning. 3 ed. ing and Management,’’ canvasses the scien- Edward F. Gilman. 2012. Delmar, Cengage tific literature and introduces the reader to At first glance, I suspected that the pub- Learning, Clifton Park, NY. 476 pages incl. our current understanding of root growth lisher grafted Dirr’s Hardy Trees and Shrubs appendices, glossary, index, full-color pho- and the effects of root pruning on regrowth (1997) with Dirr’s Trees and Shrubs for tographs, and illustrations. $129.95, Soft- in the nursery, at planting, and in the landscape Warm Climates (2002) to create Dirr’s En- cover. ISBN-13: 978-1-111-30730-1. environment. Typical of all of the chapters, cyclopedia. I was mistaken. The copy on the Gilman deftly weaves the scientific literature back cover accurately states that the Ency- ‘‘Pruning is both an art and a science’’ is into practitioner-friendly prose that enlightens clopedia combines ‘‘two classic and best- an adage that appears in a multitude of print and empowers the reader to employ the right selling books under one cover, fully updated and electronic publications. However, proper techniques. with hundreds of new , photographs, pruning—artistic expression coupled with A feature that raises the bar for currently and commentary in Dirr’s signature style.’’ research-based techniques—needs to be prac- available or impending pruning publications The author made wholesale changes to the ticed more widely in nurseries, landscapes, is Gilman’s use of more than 500 full-color text and fortified it with higher quality photo- and streetscapes. In fact, a prevailing idea photographs and illustrations that allow graphs than in his two earlier books. Also, Dirr (especially among the nescient) is that if you readers to visualize pruning techniques, terms, updated the botanical names (thankfully he can afford a pair of loppers or a chainsaw, and concepts. In some of his illustrations included their synonyms), a taxonomic neces- you know how to prune shrubs and trees Gilman simplifies his ‘‘how to’’ instructions sity that chafes horticulturists, especially stu- properly. Sadly, we know that concept is not by using red-colored branches to denote limbs dents studying materials. true. that need to be removed. This clever use of The layout of the Encyclopedia is identi- Pruning is a skill that requires knowledge color to teach readers how to make proper cuts cal to Dirr’s Hardy and Warm Climates books and practice. Happily, Gilman hit a grand slam reminds me of Ernie Christ’s 1975 Rutgers with an A to Z arrangement of taxa from rd with his 3 edition of An Illustrated Guide to Cooperative Extension Bulletin (377-A): Abelia to Ziziphus jujube. Dirr writes each Pruning. Comprised of 18 chapters, nine ap- ‘‘How to prune young and bearing apple entry in an authoritative but conversational pendices, a glossary, and 115 references, An trees.’’ This simple use of color engages our tone. The author succinctly discusses the over- Illustrated Guide to Pruning is, in my opinion, visual senses and enhances the process of all appearance and use of a species, its height the pruning bible for nurserymen, horticultur- learning how to prune properly. and width, identification features, such as ists, and arborists. The following nine appendices round-out size and color, and ornamental attributes, The first four chapters provide introductory this instructional manual: Nonconiferous trees such as fall leaf color, flowers, and fruits. information: pruning objectives and strate- requiring only moderate pruning to develop Dirr also includes the USDA cold hardiness gies; ways to minimize pruning needs with reasonably good structure; Trees often grown zone (avoiding the a and b designations) and appropriate plant selection, placement, and successfully with a multileader or multitrunk native range. He also lists and briefly describes management; and understanding the im- habit; Trees suited for training into a stan- selected varieties and cultivars. pacts of pruning on and tree biology dard; Plants suited for espalier training; Thankfully, he avoids a dry encyclopedic and health. Sample pruning specifications; A schedule approach and retains his signature style Chapters 5 through 7 define and explain the for training shade trees in the urban land- that proves to be informative, entertaining, implications of three pruning cuts—reduction, scape (‘‘Trees are like children; they require affectionate, reflective, opinionated, and heading, and removal cuts, various types of about 25 years of training to create good, solid empathetic. pruning tools that range from shears to structure that will last them a lifetime’’); I counted 134 additional taxa that were chainsaws, and timing—knowing when to Nursery production protocol for upright not included in the Hardy or Warm Climates prune fruit and ornamental trees from the trees; Trees that often form multiple trunks; books. I was pleased to see Olea europaea in nursery to the landscape. and Handy cue cards for using in the field the Encyclopedia but disappointed that Cit- Nurserymen will be interested in chapters (which can also be downloaded at www. rus was not included despite the growing 8 and 9, which address nursery tree produc- urbantree.org). trend of cultivating hardy citrus by commer- tion strategies to develop quality trees with While this book appears to be aimed at cial and residential audiences. dominant leaders, well-spaced lateral branches, professional nurserymen, arborists, and hor- The expertly laid-out photos in the well-tapered trunks, and a uniform crown. ticulturists, Gilman broadens its appeal to Encyclopedia trump the quality of photographs To satisfy the artful aspects of pruning, students. At the beginning of every chapter is in his earlier books in terms of color and Gilman devotes Chapter 10 to developing an a list of objectives and key words that are clarity. The wide shots of species and cultivars espalier, pollarding, and other forms of ‘‘ar- boldfaced and defined in the chapter. Gilman showcase their form and function in the land- chitectural pruning.’’ concludes every chapter with the following scape; the close-ups of , flowers, and Chapters 11 and 12 address the crux of three sections: ‘‘Check Your Knowledge’’ fruit beautifully complement the prose. An Illustrated Guide to Pruning—structural multiple choice questions; a cognitive ‘‘Chal- The photographs are especially important pruning. For years Dr. Gilman has written lenge Question’’ that asks the reader to discuss to readers when Dirr describes lesser known, and spoken about the importance of structural a particular concept or technique; and ‘‘Sug- uncommon species that deserve widespread or formative pruning to eliminate defects (such gested Exercises’’ that engage the student in commercial acceptance. His compelling en- as codominant stems, low-growing branches), an experiential learning activity dorsement of obscure species and accompa- to increase the life span of a tree, and to reduce An Illustrated Guide to Pruning can be nying comments may lead readers to covet potential of a tree to harm people and property. used as a reference or as a companion textbook species that include For individuals who interact with trees from for teaching nursery production and arbori- (‘‘This species will doubtfully make anyone’s the nursery to the landscape, these two chapters culture courses. Very simply, it is a must-have list of the top 50 flowering shrubs.’’); Forest- address the concepts and practices involved in book for anyone interested in learning or iera acuminate (‘‘What is it? Who cares? Why developing a tree with a strong architectural teaching the art and science of pruning. is it here?’’); and Picrasma quassiodes (‘‘Rare. framework comprised of a dominant leader Worthy? I will allow the reader to decide. and well-spaced, supportive scaffold limbs. ROBERT F. POLOMSKI I have a plantsman’s affinity for the species In the remaining chapters of the book, School of Agricultural, Forestry, and and am at a loss to explain its remoteness in Gilman discusses approaches for pruning Environmental Science, Clemson University cultivation’’).

HORTSCIENCE VOL. 47(7) JULY 2012 969 The Encyclopedia caters to green indus- Users of the Encyclopedia will enjoy the vines for flowers, fruit and fall color. The try professionals, particularly landscape 28-page section at the end of the ‘‘A–Z reader can refer to any of these lists to select designers, landscape architects, grounds Encyclopedia of Trees and Shrubs’’ titled appropriate plants for particular purposes managers, and nursery and garden center ‘‘Selecting Plants for Specific Characteristics and designs and then refer to the A–Z di- operators, who will value it as a reference or Purposes.’’ Dirr arranges the taxa in the rectory for more information. and a teaching and learning tool for their Encyclopedia into the following 15 categories: For its informative and engaging prose employees and customers. Serious gardeners flower color; flowering sequence; fragrant interspersed with more than 3,500 photo- with a facile use of botanical names also will flowers; fruit color; fall color; winter interest; graphs, the Encyclopedia has earned a spot cherish this book. As an instructor of a land- shade tolerance; salt tolerance; tolerance to on my desk. scape plant materials course, I envision the moist or wet soils; tolerance to dry soils; street Encyclopedia to be a supplement to but not and urban planting; hedging; evergreens for ROBERT POLOMSKI a substitute for the Manual of Woody Land- specimens; grouping; screens and groves; School of Agricultural, Forestry, and scape Plants. weeping or fastigiated/columnar habit; and Environmental Science, Clemson University

Corrigendum

In the article titled ‘‘Organic Soil In the abstract: as an organic soil amendment at a rate Amendment and Tillage Affect Soil Qual- of 508 m3Áha–1 (5-cm depth, equaling ity and Plant Performance in Simulated 1. ‘‘Composted dairy manure solids were 256 MgÁha–1) ..’’ The value 508 m3Áha–1 Residential Landscapes,’’ by S. Loper, applied as an organic soil amendment at should be 50.8 m3Áha–1 and the value 256 A.L.Shober,C.Wiese,G.C.Denny,C.D. a depth of 5 cm (256 MgÁha–1) ..’’ The MgÁha–1 should be 25.6 MgÁha–1. Stanley, and E.F. Gilman [HortScience value 256 MgÁha–1 should be 25.6 MgÁha–1. 3. ‘‘Plots that received compost applications 45(10):1522–1528; January 2010], there were received total N and EPA 3050 digestible a few errors in the values listed in the In the Materials and Methods: Patarateof3277 and 1385 kgÁha–1, Abstract (p. 1522) and in the Materials and respectively.’’ The values 3277 and 1385 Methods section (p. 1523, second column, 2. ‘‘Composted dairy manure solids (com- kgÁha–1 should be 327.7 and 138.5 kgÁha–1, middle paragraph): post; Agrigy, Palm Harbor, FL) were applied respectively.

970 HORTSCIENCE VOL. 47(7) JULY 2012