Table Of ContentDirr’s
Encyclopedia
of Trees and
Shrubs
Dirr’s
Encyclopedia
of Trees and
Shrubs
MICHAEL A. DIRR
TIMBER PRESS
Portland · London
To Roger Milliken—
mentor, friend, and advocate for Noble Trees
Frontispiece: Chapel Hill garden, late May 2008.
Pages 14–15: Daphniphyllum macropodum
Copyright © 2011 by Michael A. Dirr. All rights reserved.
All photographs are by the author.
Published in 2011 by Timber Press, Inc.
The Haseltine Building 2 The Quadrant
133 S.W. Second Avenue, Suite 450 135 Salusbury Road
Portland, Oregon 97204-3527 London NW6 6RJ
www.timberpress.com www.timberpress.co.uk
Printed in China
Library of Congress Cataloging-in-Publication Data
Dirr, Michael.
Dirr’s encyclopedia of trees and shrubs/Michael A. Dirr.— 1st ed.
p. cm.
Includes indexes.
ISBN 978-0-88192-901-0
1. Ornamental trees— Encyclopedias. 2. Ornamental shrubs—Encyclopedias.
I. Title. II. Title: Encyclopedia of trees and shrubs.
SB435.D57 2011
635.9v7603—dc22 2011007951
Catalog records for this book are available from the British Library.
Contents
Introduction 7
A–Z Encyclopedia of Trees and Shrubs
Abelia 16 Broussonetia 120 Clematis 194 Disanthus 274 Garrya 321
Abeliophyllum 22 Brugmansia 121 Clerodendrum 196 Distylium 274 Gaultheria 322
Abies 22 Brunfelsia 121 Clethra 197 Duranta 276 Gaylussacia 322
Abutilon 28 Buddleia 122 Cleyera 201 Edgeworthia 277 Gelsemium 323
Acacia 29 Buxus 128 Cliftonia 202 Ehretia 278 Genista 324
Acca 30 Calia 132 Cocculus 202 Elaeagnus 279 Ginkgo 326
Acer 30 Callicarpa 132 Colutea 203 Eleutherococcus 283 Gleditsia 327
Actinidia 58 Callistemon 134 Comptonia 204 Elliottia 283 Gordonia 328
Adina 62 Calluna 136 Cornus 204 Elsholtzia 284 Grevillea 330
Aesculus 63 Calocedrus 136 Corokia 224 Emmenopterys 284 Gymnocladus 330
Agarista 72 Calycanthus 139 Corylopsis 224 Enkianthus 285 Halesia 332
Agave 74 Camellia 141 Corylus 227 Epigaea 286 Hamamelis 333
Ailanthus 74 Campsis 144 Cotinus 231 Erica 287 Hebe 339
Akebia 75 Caragana 147 Cotoneaster 234 Eriobotrya 288 Hedera 339
Alangium 76 Carissa 148 Crataegus 240 Erythrina 289 Helianthemum 341
Albizia 76 Carpinus 149 Croton 245 Escallonia 289 Heptacodium 341
Allamanda 78 Carya 152 Cryptomeria 246 Eubotrys 290 Hibiscus 342
Alnus 79 Caryopteris 154 Cunninghamia 248 Eucalyptus 290 Hippophae 345
Amelanchier 82 Cassia 156 =Cupressocyparis Eucommia 291 Holboellia 345
Amorpha 85 Castanea 156 249 Eucryphia 292 Hovenia 346
Ampelopsis 86 Catalpa 158 Cupressus 251 Euonymus 292 Hydrangea 346
Andrachne 87 Ceanothus 160 Cycas 254 Eurya 298 Hypericum 359
Andromeda 87 Cedrus 163 Cyrilla 255 Euscaphis 299 Idesia 363
Antigonon 88 Celastrus 166 Cyrtomium 256 Exochorda 299 Ilex 364
Aralia 88 Celtis 167 Cytisus 256 Fagus 300 Illicium 384
Araucaria 90 Cephalanthus 169 Daboecia 258 Fallopia 303 Indigofera 388
Arbutus 90 Cephalotaxus 170 Danae 259 =Fatshedera 303 Itea 390
Arctostaphylos 92 Cercidiphyllum 172 Daphne 259 Fatsia 305 Ixora 391
Ardisia 92 Cercis 174 Daphniphyllum 264 Ficus 305 Jasminum 392
Aristolochia 94 Chaenomeles 179 Davidia 264 Firmiana 307 Juglans 395
Aronia 95 Chamaecyparis 181 Decaisnea 265 Fontanesia 307 Juniperus 397
Asimina 96 Chamaedaphne 185 Decumaria 266 Forestiera 307 Kadsura 410
Aucuba 97 Chilopsis 186 Desfontainia 266 Forsythia 308 Kalmia 410
Azara 99 Chimonanthus 186 Deutzia 267 Fothergilla 311 Kalopanax 412
Baccharis 99 Chionanthus 187 Dichroa 269 Frangula 312 Kerria 413
Bauhinia 100 =Chitalpa 189 Dicksonia 270 Franklinia 314 Koelreuteria 414
Berberis 101 Choisya 190 Diervilla 270 Fraxinus 315 Kolkwitzia 417
Betula 107 Cinnamomum 191 Diospyros 271 Fuchsia 318
Laburnocytisus 417
Bignonia 118 Cistus 192 Dipelta 272 Galphimia 319 Laburnum 418
Bougainvillea 119 Cladrastis 193 Dirca 273 Gardenia 319 Lagerstroemia 418
5
Lantana 429 Myrtus 519 Photinia 567 Rosmarinus 729 Taxodium 789
Larix 431 Nageia 520 Physocarpus 571 Rostrinucula 730 Taxus 792
Laurus 433 Nandina 520 Picea 573 Rubus 731 Tecoma 797
Lavandula 433 Neillia 523 Picrasma 580 Ruscus 732 Ternstroemia 798
Leiophyllum 434 Nerium 524 Pieris 581 Salix 733 Tetradium 799
Leitneria 435 Neviusia 526 Pinckneya 585 Sambucus 740 Teucrium 800
Leptodermis 435 Nyssa 526 Pinus 585 Santolina 742 Thuja 801
Leptospermum 436 Olea 528 Pistacia 606 Sapindus 743 Thujopsis 805
Lespedeza 437 Orixa 529 Pittosporum 608 Sarcandra 744 Tilia 806
Leucophyllum 438 Osmanthus 530 Planera 609 Sarcococca 744 Toona 812
Leucothoe 439 Ostrya 537 Platanus 610 Sassafras 747 Torreya 813
Leycesteria 441 Oxydendrum 538 Plumbago 612 Schizophragma 748 Trachelospermum
Ligustrum 442 Pachysandra 538 Podocarpus 613 Sciadopitys 749 814
Lindera 449 Palms 541 Poliothyrsis 615 Sequoia 749 Triadica 816
Liquidambar 451 Butia 541 Poncirus 616 Sequoiadendron 750 Trochodendron 817
Liriodendron 454 Chamaerops 543 Populus 617 Serissa 752 Tsuga 818
Lithocarpus 456 Livistona 543 Potentilla 621 Sesbania 752 Ulmus 821
Lonicera 457 Phoenix 543 Prinsepia 623 Shepherdia 753 Ungnadia 829
Loropetalum 466 Rhapidophyllum Prunus 624 Sinojackia 753 Vaccinium 830
Lyonia 470 545 Pseudocydonia 651 Skimmia 754 Vernicia 835
Maackia 471 Rhapis 545 Pseudolarix 651 Smilax 755 Viburnum 835
Maclura 472 Sabal 546 Pseudotsuga 652 Sorbaria 755 Vinca 871
Magnolia 472 Serenoa 547 Ptelea 653 Sorbus 756 Vitex 873
Mahonia 496 Syagrus 548 Pterocarya 654 Spiraea 759 Vitis 875
Malus 500 Trachycarpus 548 Pterostyrax 655 Stachyurus 766 Weigela 877
Malvaviscus 507 Washingtonia 549 Punica 656 Staphylea 767 Wisteria 878
Mandevilla 508 Parkinsonia 551 Pyracantha 658 Stephanandra 768 Wollemia 882
Melia 508 Parrotia 551 Pyrus 659 Stewartia 769 Xanthoceras 883
Menispermum 508 Parrotiopsis 555 Quercus 666 Styphnolobium 773 Xanthocyparis 884
Mespilus 510 Parthenocissus 555 Rhamnus 692 Styrax 774 Xanthorhiza 885
Metasequoia 510 Passiflora 558 Rhaphiolepis 693 Sycopsis 777 Yucca 885
Microbiota 512 Paulownia 558 Rhododendron 695 Symphoricarpos 779 Zamia 886
Millettia 512 Paxistima 560 Rhodotypos 711 Symplocos 780 Zanthoxylum 887
Mitchella 512 Persea 561 Rhus 712 Syringa 781 Zelkova 888
Morus 513 Phellodendron 562 Ribes 717 Taiwania 788 Zenobia 891
Musa 515 Philadelphus 563 Robinia 719 Tamarix 789 Ziziphus 892
Myrica 516 Phillyrea 566 Rosa 721
Selecting Plants for Specific Characteristics or Purposes Street and Urban Planting 920
895 Hedging 921
Flower Color 895 Evergreens for Specimens, Groupings, Screens, and
Flowering Sequence 900 Groves 921
Fragrant Flowers 904 Weeping or Columnar Habit 922
Fruit 905 Vines for Flowers, Fruit, and Fall Color 923
Fall Color 909
Winter Interest 914 Conversion Table for Metric Measurements 924
Shade Tolerance 915 Hardiness Zones 924
Salt Tolerance 917 Acknowledgments 924
Tolerance to Moist or Wet Soils 918 Index of Botanical Names 925
Tolerance to Dry Soils 918 Index of Common Names 946
6
Introduction
Timber Press and I have developed a petition among breeders and intro- Take variegated leaf cultivars of
symbiotic relationship in our quest/ ducers who have similar plants. The Abelia =grandiflora, now numbering
journey to produce worthy books that financial advantage is often weighted about 17. Many are unstable, produc-
gardeners would embrace and enjoy. toward the first mover. Testing and ing green, albino, and other shoot
Dirr’s Hardy Trees and Shrubs (1997), t rialing for many woody plants are min- permutations not typical of the origi-
Dirr’s Trees and Shrubs for Warm Cli- imal, and marketing supersedes the nal cultivars. I have bred, evaluated,
mates (2002), Hydrangeas for Ameri- reality of performance. In this tome, tested, trialed, selected, grown, and
can Gardens (2004), and Viburnums I provide the best assessment pos- introduced abelias, and ‘Hopleys’
(2006) have found niches in the gar- sible based on testing data, research (‘Aghop’), rebranded Twist of Lime™,
den and nursery circles. This encyclo- reports, performance in nurseries and has been one of the most stable, con-
pedia builds on the foundations of the gardens, and evaluations at our breed- sistently true to type. Does this mean
Hardy and Warm Climate books, with ing company in Watkinsville, Georgia, that someone else could have a differ-
more than 3,500 photographs of spe- Plant Introductions, Inc. (www.plant ent experience? Absolutely!
cies and cultivars in 380 genera, with introductions.com). Cross-referencing the Hydrangea
an emphasis on the best new intro-
ductions of the past ten to 15 years.
The garden and nursery worlds have
changed dramatically in that time.
Independent garden centers have
waned, while Home Depot, Lowe’s,
Wal-Mart, and other mega-chains
command greater percentages of
green good sales. Be advised that
the mass merchandisers are actively
p ursuing new plants to entice custom-
ers. Reflecting these advances are the
increases in plant patents, which allow
the owner to control the licensing of
the product. In 1996 (66 years after
the Plant Patent Act was instituted),
approximately 10,000 plant patents
were granted; in 2010, the n umber
was over 21,000. This increase
reflects the desire of breeders and
introducers to protect their intellec-
tual property. Also, many plants are
not patented, but introduced for the
greater good. The new plant tsunami
literally swamps horticulturists’ and
gardeners’ will and ability to stay
current. Lagerstroemia Cherry Dazzle®, a superior red-flowered, genetically
The rush to market is based on com- compact selection from the author’s breeding program.
7
paniculata cultivar trials at the Royal garden, and many readers commented watched Knock Out® move around
Horticultural Society (www.rhs.org.uk) positively about “seeing” it. the cul-de-sac and throughout the
with my Georgia evaluations reflects Unfortunately, the home and gar- neighborhood.
dichotomies of results. For example, den in the 2002 book are no more, This garden was spiritually and psy-
RHS Trials Bulletin 23 (December as we sold and moved to Chapel Hill, chologically essential to Bonnie’s, my,
2008) evaluated more than half of the North Carolina, for medical reasons, and Susy’s well-being. Susy, who car-
more than 80 known cultivars. Best to care for our youngest daughter, ried the gene for cystic fibrosis, was
(three stars) were ‘Big Ben’ (lousy in Suzanne. After existing in an apart- blessed to have two double-lung trans-
Georgia), ‘Dolly’ (lousy in Georgia), ment for six months (no garden), we plants at UNC-CH and live a rich, full,
‘Kyushu’ (lousy in Georgia), Limelight™ decided to purchase a home, develop vibrant, and meaningful life. We lost
(very good in Georgia), Pinky Winky™ a garden, and live a normal life. The our beloved Susy to chronic rejection
(poor in Georgia), and so forth. The landscape (initially with bargain-base- in January 2008.
take-home lesson: biology is shades ment butterflybushes, abelias, and Books are written on dealing with
of gray, and dogmatic acceptance Indian hawthorns—all eliminated) was grief, but Bonnie and I find inner peace
of anyone’s results is foolish. Use transformed into a garden with color, with each other and in the garden.
these data as guides to the superior fragrance, diversity, and seasonality. Bonnie stated it best—there is joy
introductions. In part, it was also a test site for many in nurturing and loving living things
“Show me your garden and I shall new plants from our breeding program to their greatest genetic potential.
tell you what you are.” This Alfred Aus- and those of colleagues. We sold our place in Chapel Hill and
tin quote captures Bonnie’s and my The neighbors noticed, commented, returned to Athens, where in 2009
love of garden-making. As an introduc- queried about the roses (Knock Out®), we purchased a new home on an
tion to the Warm Climate book, I textu- dwarf crapemyrtles (Razzle Dazzle® acre and started the garden journey
ally and photographically walked the series), and lantanas (Chapel Hill anew. Realizing that planting space
reader through our then 23-year-old series), and others. With delight, I was being rapidly consumed, we pur-
Hydrangea macrophylla hybrid selections at Plant Introductions, Inc.
8
chased the contiguous lot as well.
It was choked with Chinese privet
(Ligustrum sinense), kudzu (Pueraria
montana var. lobata), and muscadine
(Vitis rotundifolia), all quickly cleared;
a specimen white oak (Quercus alba),
a 50-ft.-high, four-trunked black tupelo
(Nyssa sylvatica), and flowering dog-
wood (Cornus florida) were preserved.
We are enjoying pencil farming this
and the home site, dreaming about
what may metamorphosize.
In autumn 2010, we planted a
sinuous shrub border that effectively
screens the new lot from the street.
Neighbors commented and asked
about the identity of the plants. I men-
tioned that 14 different viburnums
were utilized. They were mystified for,
in the South, “viburnum” simply does
not resonate. Hopefully, they will enjoy
and learn as the border matures.
Plant Introductions, Inc., continues
to develop. My two partners are Jeff
Lantana camara ‘Chapel Hill Yellow’ in production; note flower quantity.
Knock Out® roses planted over a French drain between drive and neighbor’s
fence, four years after planting: Blushing Knock Out®, ‘Carefree Sunshine’, and
Knock Out®, the original red. Chapel Hill, North Carolina.
9
