AMERICAN STANDARD

FOR NURSERY STOCK

ANSI Z60.1–2004

Approved May 12, 2004

DEDICATION

in memory of Ronnie Swaim, Gilmore Plant & Bulb Co., Inc. (NC)

Copyright 2004 by American Nursery & Landscape Association

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or

mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in

writing from the publisher.

American Nursery & Landscape Association

1000 Vermont Avenue, NW, Suite 300

Washington, DC 20005

www.anla.org

ISBN 1-890148-06-7

Foreword ..................................................................... i

Container size specifications .................................... ii

Container class table .............................................. iii

In-ground fabric bag specifications........................... iii

How to use this publication ...........................................iv

Horticultural standards committee...................................vi

Canvass list ................................................................vii

Section1: Shade and Flowering Trees

1.1.1 Required specifications ........................................ 1

1.1.1.1 Plant size intervals............................................ 1

1.1.1.2 Methods of caliper and height measurement........ 1

1.1.2 Optional specifications and quality designations..... 2

1.1.2.1 Height and caliper ........................................... 2

1.1.2.2 Transplanting requirements................................ 2

1.1.2.3 Specimen or quality grade designation............... 2

1.1.2.4 Height of branching—street trees ....................... 2

1.1.2.5 Trees for other uses........................................... 3

1.2.1 Type 1 shade trees .............................................. 3

1.2.2 Type 2 shade trees .............................................. 5

1.2.3 Type 3 small upright trees .................................... 6

1.2.4 Type 4 small spreading trees ................................ 7

1.3.1 Shrub form trees ................................................. 8

1.3.1.1 Definition ........................................................ 8

1.3.1.2 Specification ................................................... 9

1.3.1.3 Measurement................................................... 9

1.3.2 Clump form and multi-stem trees............................ 9

1.3.2.1 Definitions ....................................................... 9

1.3.2.2 Specification ................................................. 10

1.3.2.2.1 Clump form trees......................................... 10

1.3.2.2.2 Multi-stem trees ........................................... 10

1.3.2.3 Caliper measurements—clump form and multi-stem

trees ..................................................................... 10

1.3.2.4 Root ball sizes—shrub form, clump form and multistem

trees.............................................................. 11

1.3.2.4.1 Root ball diameters—shrub form trees............ 11

1.3.2.4.2 Root ball diameters—clump form trees ........... 11

1.3.2.4.2 Root ball diameters—multi-stem trees ............. 11

1.5.1 Nursery grown—spread of roots......................... 13

1.5.2 Collected—spread of roots................................. 14

1.6.1 Root ball diameters—field grown trees................. 15

1.6.2 Trunk in center of root ball................................. 17

1.6.3 Root ball depths ................................................ 17

1.6.4 Burlapping ....................................................... 18

1.6.5 Ball-supporting devices ...................................... 18

1.6.6 Collected ......................................................... 18

1.6.7 Plantation grown............................................... 19

1.6.8 Field potted or field boxed ................................. 19

CONTENTS

AMERICAN NURSERY & LANDSCAPE ASSOCIATION

1.6.9 Processed balled............................................... 19

1.6.10 Use of digging machines ................................ 19

Figure 1—Caliper and branching height......................... 3

Figure 2—Measurement—type 2 shade trees .................. 5

Figure 3—Type 3 small upright trees............................... 6

Figure 4—Type 4 small spreading trees .......................... 7

Figure 5— Multi-stem, clump form, and shrub form trees ...11

Figure 6—Palms......................................................... 13

Figure 7—Measurement—field grown trees ................... 14

Figure 8—Example: trunk in center of root ball .............. 17

Figure 9—Measurement of root ball depths ................... 18

Table 1—Height/caliper relationship for type 1 shade trees ....4

Table 2—Height, caliper, and branching relationships—

type 3 small upright trees ......................................... 6

Table 3—Branching—type 4 small spreading trees........... 7

Table 4—Root ball sizes for shrub form and multi-stem trees...12

Table 5—Caliper/height/root spread relationship—

nursery grown bare root trees................................. 13

Table 6—Root ball diameters—field grown trees ............ 16

Table 7—Root ball diameters—processed balled trees .... 19

Table 8—Container class guidelines—shade and

flowering trees...................................................... 20

Table 9—Fabric bag sizes-trees ................................... 22

Section 2: Deciduous Shrubs

2.1.1—Required specifications .................................... 23

2.1.1.1 Plant size intervals.......................................... 23

2.1.1.2 Definition of “cane”........................................ 23

2.1.1.3 Spread and height measurements .................... 23

2.1.2 Optional specifications and quality designations... 24

2.1.2.1 Minimum number of canes .............................. 24

2.1.2.2 Transplanting or root pruning .......................... 24

2.1.2.3 Specimen designation .................................... 24

2.2.1 Type 0—Tender shrubs....................................... 24

2.2.2 Type 1—Small or dwarf .................................... 25

2.2.3 Type 2—Intermediate ........................................ 26

2.2.4 Type 3—Large or tall ......................................... 27

2.3.1 Nursery grown—spread of roots......................... 28

2.3.2 Collected—spread of roots................................. 29

2.4.1 Root ball diameters—field grown deciduous shrubs ...29

2.4.2 Plant in center of root ball .................................. 30

2.4.3 Root ball depths ................................................ 31

2.4.4 Burlapping ....................................................... 31

2.4.5 Ball supporting devices ...................................... 31

2.4.6 Field potted plants............................................. 31

2.4.7 Processed balled plants...................................... 32

2.4.8 Collected plants ................................................ 32

2.4.9 Plantation grown plants ..................................... 32

2.4.10 Use of digging machines ................................ 32

Figure 10—Types of deciduous shrubs.......................... 27

Figure 11—Typical type 2 intermediate deciduous shrubs ...28

Figure 12—Center of plant in center of root ball ............ 30

Figure 13—Measurement of field grown deciduous shrubs....30

Figure 14—Ball depths: field grown deciduous shrubs .... 31

Table 10—Height or spread relationship to number of canes

and spread of roots or root ball diameter—

type 0 deciduous shrubs ........................................ 25

Table 11—Height or spread relationship to number of canes

and spread of roots or root ball diameter—

type 1 deciduous shrubs ........................................ 26

AMERICAN NURSERY & LANDSCAPE ASSOCIATION

Table 12— Height or spread relationship to number of

canes and spread of roots or root ball diameter—

type 2 deciduous shrubs ........................................ 26

Table 13—Height or spread relationship to number of canes

and spread of roots or root ball diameter —

type 3 deciduous shrubs ........................................ 28

Table 14—Container class guidelines—deciduous shrubs....33

Table 15—Fabric bag sizes—deciduous shrubs ............. 34

Section 3: Coniferous Evergreens

3.1.1 Required specifications ...................................... 35

3.1.1.1 Plant size intervals.......................................... 35

3.1.1.2 Spread and height measurements .................... 35

3.1.2 Shearing designations ....................................... 36

3.1.3 Determining root ball, container, or fabric bag size ...37

3.1.4 Optional specifications and quality designations... 37

3.1.4.1 Height and spread ......................................... 37

3.1.4.2 Transplanting or root pruning .......................... 37

3.1.4.3 Specimen or quality grade designation, collected

stock.................................................................... 38

3.1.4.4 Minimum or maximum caliper ......................... 38

3.1.5 Dwarf conifers .................................................. 38

3.2.1 Type 1 creeping or prostrate .............................. 38

3.2.2 Type 2 semi-spreading....................................... 38

3.2.3 Type 3 broad spreading, globe, and compact upright... 39

3.2.4 Type 4 cone type (pyramidal) ............................. 40

3.2.5 Type 5 broad upright......................................... 42

3.2.6 Type 6 columnar type ........................................ 43

3.3.1 Root ball diameters—field grown coniferous

evergreens ......................................................... 44

3.3.1.1 Natural and semi-sheared ............................... 47

3.3.1.2 Sheared........................................................ 47

3.3.1.3 Dwarf varieties .............................................. 47

3.3.2 Trunk in center of ball ........................................ 47

3.3.3 Ball depths ...................................................... 47

3.3.4 Burlapping ....................................................... 48

3.3.5 Ball supporting devices ...................................... 48

3.3.6 Collected ......................................................... 48

3.3.7 Plantation grown.............................................. 49

3.3.8 Field potted ...................................................... 49

3.3.9 Use of digging machines ................................... 49

Figure 15—Measurement—types 1 and 2 coniferous

evergreens ........................................................... 36

Figure 16—Measurement—type 3 coniferous evergreens....40

Figure 17—Measurement —type 4 coniferous evergreens...41

Figure18—Determining average height —type 4 coniferous

evergreens ........................................................... 42

Figure 19—Measurement—type 5 coniferous evergreens....43

Figure 20—Measurement —type 6 coniferous evergreens...44

Figure 21—Example: trunk in center of earth ball........... 47

Figure 22—Ball depths—coniferous evergreens ............. 48

Table 16—Type 3 coniferous evergreens....................... 40

Table 17—Type 4 coniferous evergreens....................... 41

Table 18—Type 5 coniferous evergreens....................... 42

Table 19—Type 6 coniferous evergreens....................... 43

Table 20—Ball sizes—coniferous evergreens ................. 46

Table 21—Container class guidelines—natural,

semi-sheared, or lightly sheared evergreens.............. 50

Table 22—Fabric bag sizes—coniferous evergreens....... 52

Section 4: Broadleaf Evergreens

4.1.1 Required specifications ...................................... 53

4.1.1.1 Plant size intervals.......................................... 53

4.1.1.2 Spread and height measurements .................... 53

4.1.2 Shearing designations ....................................... 54

4.1.3 Determining root ball, container, or fabric bag size ...54

4.1.4 Optional specifications and quality designations... 55

4.1.4.1 Height and spread ......................................... 55

4.1.4.2 Transplanting or root pruning .......................... 55

4.1.4.3 Specimen or quality grade designation,

collected stock ....................................................... 55

4.1.4.4 Minimum or maximum caliper ......................... 55

4.1.5 Dwarf broadleaf evergreens ............................... 55

4.2.1 Type 1—Spreading type .................................... 56

4.2.2 Type 2—Semi-spreading type ............................. 56

4.2.3 Type 3—Broad spreading, globe, or compact

upright type.......................................................... 57

4.2.4 Type 4—Broad upright type ............................... 58

4.2.5 Type 5—Cone type ........................................... 59

4.2.6 Type 6—Columnar type ..................................... 60

4.3.1 Root ball diameters—field grown broadleaf

evergreens ........................................................... 61

4.3.1.2 Sheared........................................................ 63

4.3.1.3 Dwarf varieties .............................................. 63

4.3.2 Trunk in center of ball ....................................... 63

4.3.3 Ball depths ...................................................... 63

4.3.4 Burlapping ...................................................... 64

4.3.5 Ball supporting devices ...................................... 64

4.3.6 Collected ......................................................... 64

4.3.7 Plantation grown............................................... 65

4.3.8 Field potted ..................................................... 65

4.3.9 Use of digging machines .................................. 65

Figure 23—Measurement—type 1 broadleaf evergreens ....56

Figure 24— Measurement—type 2 broadleaf evergreens ...57

Figure 25—Measurement—type 3 broadleaf evergreens ....58

Figure 26—Measurement—type 4 broadleaf evergreens ....59

Figure 27—Measurement—type 5 broadleaf evergreens ....60

Figure 28—Example: trunk in center of earth ball........... 63

Figure 29—Ball depth measurement ............................. 64

Table 23—Type 3 broadleaf evergreens ....................... 57

Table 24—Type 4 and 5 broadleaf evergreens .............. 58

Table 25—Type 6 broadleaf evergreens ....................... 60

Table 26—Ball sizes—broadleaf evergreens.................. 62

Table 27—Container class guidelines—natural, semi, or

lightly sheared ..................................................... 66

Table 28—Fabric bag sizes—types 4 and 5 broadleaf

evergreens ........................................................... 67

Section 5: Rose Grades

5.4.1 Large grower.................................................... 70

5.4.2 Small grower.................................................... 70

5.4.3 Root system ...................................................... 71

5.5.1 Standard tree rose 36” (91 cm) ....................... 71

5.5.2 Patio tree rose 18 inches (50 cm)...................... 71

5.5.3 Mini-tree rose—(miniature varieties).................... 71

Figure 30—Hybrid tea, tea, grandiflora, etc., roses ....... 69

Figure 31—Climbing roses.......................................... 69

Figure 32—Polyantha roses......................................... 70

Figure 33—Floribunda roses ....................................... 70

Figure 34—Tree roses ................................................ 72

Section 6: Young Plants

AMERICAN NURSERY & LANDSCAPE ASSOCIATION

6.1.1 Cultural history or age specifications ................... 73

6.1.1.1 Propagation and cultural history codes ............ 73

6.1.2 Quality definition ............................................. 74

6.1.3 Unrooted cuttings ............................................. 74

6.1.5 Pruning ........................................................... 74

6.3.1 Slow grower (dwarf and semi-dwarf).................. 75

6.3.2 Medium grower ............................................... 75

6.3.3 Fast grower ..................................................... 75

6.4.1 Type 1—No stems............................................ 75

6.4.2 Type 2—Single stem......................................... 75

6.4.2.1 Spreading..................................................... 75

6.4.2.2 Semi-spreading.............................................. 76

6.4.2.3 Globe........................................................... 76

6.4.2.4 Medium upright ............................................. 76

6.4.2.5 Upright ........................................................ 76

6.4.3 Type 3—Stoloniferous....................................... 76

6.4.4 Type 4—Rhizomatous, tuberous, or fibrous roots ....76

6.4.5 Type 5—Fans .................................................. 76

6.4.6 Type 6—Bulbs, corms ....................................... 77

6.4.7 Type 7—Vines ................................................. 77

6.4.8 Conifer plantation and reforestation plants .......... 77

6.6.1 Plug cell specifications ....................................... 77

Section 7: Fruit Tree Grades

7.1.1 Quality definition ............................................. 78

7.1.2 Cultural designations ........................................ 78

7.1.2.1 Unrooted cuttings .......................................... 78

7.2.1 Deciduous ....................................................... 79

7.2.2 General .......................................................... 79

7.2.3 Processed balled.............................................. 80

7.2.4 Fruit seedlings.................................................. 81

7.2.4.1 Caliper measurement..................................... 81

7.2.4.2 Special specification...................................... 81

7.2.4.3 Vegetatively propagated/micropropagated fruit

stock.................................................................... 81

7.2.4.3.1 Special specification (root system) ................. 81

7.2.5 Citrus ............................................................. 82

Table 29—Height/caliper relationship for standard apple,

sweet cherry, peach, almond, nectarine, pear, apricot,

prune, and plum (one and two years) ...................... 79

Table 30—Height/caliper relationship for standard sourcherry

and dwarf peach, pear, nectarine, apricot, prune

and plum (on clonal rootstock only) ......................... 80

Table 31—Height/caliper relationship for dwarf apple

(including clonal rootstock and interstem trees).......... 80

Table 32—Ball sizes—processed balled fruit trees .......... 81

Table 33—Apple rootstocks/interstems ......................... 82

Table 34—Pear rootstocks........................................... 83

Table 35—Peach, nectarine, and almond rootstocks....... 83

Table 36—Plum and apricot rootstocks ......................... 84

Table 37—Cherry rootstocks ....................................... 84

Section 8: Small Fruits

8.1.1 Quality definitions ............................................ 85

8.1.2 Designation..................................................... 85

8.1.2.1 Unrooted cuttings .......................................... 85

8.2.1 Raspberries ..................................................... 86

8.2.1.1 Sucker and root cutting plants......................... 86

AMERICAN NURSERY & LANDSCAPE ASSOCIATION

8.2.2 Transplanted raspberries ................................... 86

8.2.3 Dewberries, blackberries, boysenberries,

youngberries ........................................................ 86

8.2.3.1 Root cuttings.................................................. 86

8.2.4 Transplanted blackberries .................................. 86

8.2.5 Currants........................................................... 86

8.2.6 Blueberries ...................................................... 87

8.2.7 Gooseberries................................................... 87

8.2.8 Grape vines ..................................................... 87

8.2.9 Strawberry plants.............................................. 87

8.2.10 Asparagus crowns .......................................... 87

Figure 35—Strawberries—minimum requirements .......... 88

Section 9: Understock

9.1.1 Quality definition ............................................. 89

9.1.2 Designation..................................................... 89

9.1.2.1 Unrooted cuttings ......................................... 90

9.2.1 Measurement designation ................................. 90

9.3.1 Fruit and nut seedlings—seed-propagated stock ... 90

9.3.1.1 Seedlings with limbs ...................................... 90

9.3.1.2 Root descriptions........................................... 90

9.3.2 Vegetatively propagated plants.......................... 91

9.3.2.1 From layering ............................................... 91

9.3.2.2 Hardwood cuttings........................................ 91

9.3.2.3 Softwood cuttings.......................................... 91

9.3.3 Unclassified...................................................... 91

Section 10: Seedling Trees and Shrubs

10.1.1 Quality definition ............................................ 93

10.1.2 Designation................................................... 93

10.2.1 Deciduous or hardwood ................................. 94

10.2.2 Coniferous evergreens .................................... 95

Table 38—Minimum heights and root lengths for seedling

calipers................................................................ 94

Table 39—Minimum calipers for seedling heights and root

lengths................................................................. 94

Table 40—Coniferous evergreen seedlings.................... 95

Section 11: Bulbs, Corms, and Tubers

11.19.1 Double nose ............................................... 100

AMERICAN NURSERY & LANDSCAPE ASSOCIATION

11.19.2 Round........................................................ 101

Section 12: Herbaceous Perennials,

Ornamental Grasses, Groundcovers,

and Vines

12.1.1 Types (form in which marketed):..................... 103

12.1.2 Propagation methods..................................... 103

12.1.3 Container grown plants ................................ 104

12.2.1 Astilbe ........................................................ 104

12.2.2 Dicentra—bleeding Heart ............................. 104

12.2.3 Hemerocallis—Daylily .................................. 104

12.2.4 Hosta ssp.—Funkia....................................... 105

AMERICAN NURSERY & LANDSCAPE ASSOCIATION

12.2.5 Iris ............................................................. 105

12.2.6 Paeonia—Peony .......................................... 105

12.2.7 Papaver orientale—0riental Poppy ................. 106

12.3 Other herbaceous perennials............................. 106

12.4 Ornamental grasses ......................................... 107

12.5 Groundcovers.................................................. 107

12.6 Vines .............................................................. 107

Figure 36—Examples of typical grades for Hemerocallis...105

Figure 37—Examples of typical sizes for Paeonia ........ 106

Section 13: Christmas Tree Standards...108

Appendix A: Glossary .............................................. 109

Appendix B: Metric equivalents ................................. 112

Appendix C: Letter of Recommendation ...................... 113

i

One of the early activities of the American Nursery & Landscape Association, formerly the American

Association of Nurserymen, was the development of a standardized system of sizing and describing

plants to facilitate the trade in nursery stock. Since 1921, the Association has maintained an active

committee on standards. Its first edition of "Horticultural Standards" was published in 1923. From time

to time, these standards were revised and expanded to meet the needs of the industry.

After World War II the Association elected to make the standards a national standard by adhering to the

procedures of the American Standards Association. The first edition published under the procedures of

the American Standards Association (forerunner of the current American National Standards Institute,

or “ANSI”) was published on June 22, 1949.

The revisions included in the 2004 edition were developed by the Association's Horticultural Standards

Committee from January, 1997, through May, 2003. The proposed revisions were then submitted to

interested national and regional societies, associations, companies, individuals, and government

agencies for their review and endorsement.

The following manuals are suggested for general nomenclature use:

Box 118, NL-2770 AC BOSKOOP, The Netherlands. 5th Revised Ed., 1995.

1996.

of Agricultural Sciences, University of California, February, 1979.

The following botanical manuals are suggested for nomenclature as well as descriptive and technical

data:

1971.

ii

If only container class is stated, the specification is incomplete, and the Standard does not provide a

corresponding minimum plant size (but see exception in Section 12 for certain perennials). Tables

throughout the Standard provide guidelines to determine the appropriate container class for the specified

plant size (See Tables 8, 14, 21, and 27).

Specifications: Properly written specifications in catalogues or contract documents that are intended to

be in accordance with the Standard must refer to a container class in accordance with the Container

Class Table shown below, using the “#” symbol. Containers marketed and sold that indicate a “trade”

or “#” designation must have volumes within the ranges shown in order to comply with the Standard.

However, parties to a transaction may agree that nursery stock will be in an “unclassified” container,

which is a container with a volume not included within the recommended container class volume ranges.

Relation of Container Classes with Imperial Volumes: Each container class includes a range of

acceptable container volumes, and is not limited to a single container volume (e.g., a certain number of

“gallons”). The volume ranges for container classes #1 through #100 include the volume of a container

that, if such a container were manufactured, would hold the equivalent number of gallons as the

container class number. Standard users should refer to container manufacturers’ volume specifications

Small Plant Containers (“SP” designation): Generally, containers commonly referenced in the industry

as ‘4-inch’ or ‘quart’ containers are #SP4 containers (1 qt. = 57.75 cubic inches). If growers, buyers or

specifiers include dimension measurements or imperial volume references, they are encouraged to also

specify ‘round’ or ‘square,’ and to reference the appropriate container classification in the Container

Retail Consumer Transactions: The Standard is only applicable to nursery stock transactions within the

trade, and does not apply to retail consumer transactions. The Standard does not recognize or sanction

the practice of using only an imperial volume or dimension measurement of a certain container to

purport to indicate the size of a plant in retail consumer transactions.

Wooden Box Size Equivalents: For purposes of the Container Class Table, wooden box size

“equivalent” indicates that a wooden box size may be specified in lieu of the indicated equivalent

container class, and nursery stock in an equivalent wooden box size shall be accepted in the trade as in

conformance with a specification for container-grown nursery stock in the equivalent container class

indicated, and vice-versa. Wooden boxes are not required to have volumes that are “equal to” or within

the volume range of the indicated equivalent container class, or vice-versa.

iii

#SP1 6.5 - 8.0 106 - 131

#SP2 13.0 - 15.0 213 - 246

#SP3 20.0 - 30.0 328 - 492

#SP4 51 - 63 836 - 1033

#SP5 93 - 136 1524 - 2229

#1 152 - 251 2492 - 4115

#2 320 - 474 5246 - 7770

#3 628 - 742 10285 - 12164

#5 785 - 1242 12860 - 20360

#7 1337 - 1790 21913 - 29343

#10 2080 - 2646 34090 - 43376

#15 2768 - 3696 45376 - 60589

#20 4520 - 5152 74096 - 84457 20-inch box

#25 5775 - 6861 94669 - 112472 24-inch box

#45 9356 – 11,434 153317 – 187377 36-inch box

#65 13514 - 16517 221456 – 246051 42-inch box

#95/100 20790 – 25410 340686 - 416394 48-inch box

Recommended minimum fabric bag diameters, depths and cubic volumes are as follows:

10 inches 11 inches 864 cubic inches

12 inches 11 inches 1244 cubic inches

14 inches 13 inches 2001 cubic inches

16 inches 13 inches 2614 cubic inches

18 inches 15 inches 3817 cubic inches

20 inches 15 inches 4712 cubic inches

22 inches 17 inches 6462 cubic inches

24 inches 17 inches 7691 cubic inches

iv

A. General Information.

The purpose of the American Standard for Nursery Stock is to provide buyers and

sellers of nursery stock with a common terminology in order to facilitate transactions

involving nursery stock. For instance, the standards establish common techniques for (a)

measuring plants, (b) specifying and stating the size of plants, (c) determining the proper

relationship between height and caliper, or height and width, and (d) determining whether

a root ball or container is large enough for a particular size plant. In other words, this

book is a communication tool, and does not provide buyers with any assurance of the

health or quality of the nursery stock being specified or sold.

In order to locate the specifications for a particular plant, you should know (a)

what type of plant it is, such as whether it is a shade or flowering tree, a coniferous or

broadleaf evergreen, a young plant (seedlings, ground covers, or lining out stock), a

perennial or bulb, etc., (b) the growth habit of the particular species, (e.g., upright,

conical, spreading, multi-stemmed, etc.), and (c) the method of production of the plant

and the manner in which the plant will be sold (e.g., balled and burlapped, bare root,

containerized, etc.).

B. Organization and Procedure

1. Locate the plant group to which the plant belongs. There are thirteen plant groups:

Shade and Flowering Trees, Deciduous Shrubs, Coniferous Evergreens, Broadleaf

Evergreens, Roses, Young Plants, Fruit Trees, Small Fruits, Understock, Seedlings,

Bulbs, Corms, and Tubers, Perennials, and Christmas Trees.

2. Locate the section within that plant group which most likely contains the type of

information you want to find. The first portion of each plant group section contains

general information on how the plants in that group are measured, the conventions

regarding how measurements are to be stated, and how different types of plants within

the plant group are divided. Each plant group is further divided depending on the most

important considerations for plants in that group. The sections for trees and shrubs, for

instance, are divided based on growth habit and methods of production and sale. Other

sections are divided based on propagation methods, specific plant families within the

plant group, or other factors.

Examples of plant types within certain plant groups are only to clarify the factors used to

determine plant types within each section. Only a few examples are listed, and are not

complete lists of all genera within each plant type. Users must have horticultural

knowledge or access to horticultural resources to determine the plant type of an unlisted

species.

v

3. If you are unable to locate the information under the first plant group selected, you

should go back to the Table of Contents and determine whether there may be another

plant group to which the plant belongs.

4. The Appendix provides both a glossary of terms used in the Standard as well as a

metric conversion table

American Standard for Nursery Stock (ANSI Z60.1-2004)

vi

The ANLA Horticultural Standards Committee oversees the administration of the revisions to the

committee for various periods of time between 1997 and 2004:

Alan M. Jones, Manor View Farm Inc.

Bert T. Swanson, Swanson's Nursery Consulting Inc

Barry Hargrove, Southern Hills Country Club

Bradley F. Brown, Glacier Nursery Inc

Charles H. Huecker, Weeks Wholesale Rose Grower Inc

Dave Fujino, Hines Horticulture Inc

David Byers, Byers Wholesale Nursery Inc

David M. Taylor, Concord Nurseries Inc

E.B. Gee, III, Heartland Nursery Company

Earl F. Ervey, Blue Sterling Nursery

Edward F. Gilman, University of Florida

Frank E. Janosz, English Gardens Nursery

Frank Hopkins, Horticultural Materials/Systems Inc

Gary W. Watson, The Morton Arboretum

Hugh K. Steavenson, Forrest Keeling Nursery

J. Frank Schmidt, III, J Frank Schmidt & Son Co

Janet Rademacher, Monrovia Growers Inc

Joanne C. Kostecky, Joanne Kostecky GARDEN DESIGN Inc

Joe Burks, Certified Roses Inc

Joseph F. Jamison, Jr, Brandywine Nurseries Inc

Larry Burks, Certified Roses Inc

Leon Taylor, Greenleaf Nursery Co

Loren Blum, English Gardens Nursery

Louis Hillenmeyer, III, Louis’ Flower Power Shops

M.E. Gardner, Stribling’s Nurseries Inc

Mark Buchholz, Monrovia Growers Inc

Mark Dehmlow, Swede Valley Inc

Martha Simon Pindale, Bluemount Nurseries Inc

Paul Pagliarini, Central Nurseries Inc

R. Wayne Mezitt, Weston Nurseries Inc

Richard B. Campbell, Campbell’s Nursery & Garden Center

Richard Bocci, Carlton Plants

Richard J. Henkel, Princeton Horticultural Services

Robert Terry, Fisher Farms LLC

Roger F. Fick, Wilson Nurseries Inc

Ronald R. Amos, Evergreen Nursery Co Inc

Ronnie Swaim, Gilmore Plant & Bulb Co Inc

Steve Batka, Zelenka Nursery LLC

Thomas Pinney, Jr., Evergreen Nursery Co Inc

Timothy Bailey, Bailey Nurseries Inc

Todd Erickson, Meadow Lake Nursery Co

Tom Vanicek, Grow Northeast

William S. Stensson, Sheridan Nurseries Limited

ANLA Staff Administrator, Warren A. Quinn

American Standard for Nursery Stock (ANSI Z60.1-2004)

vii

Consensus for this standard was achieved by use of the Canvass Method.

The following organizations participated in the revisions of this standard prior to submittal to

ANSI. Inclusion of this list does not necessarily imply that the organization concurred with the

submittal of the proposed standard to ANSI.

American Forests Historic Trees

Associated Landscape Contractors of America

Association of Professional Landscape Designers

Champ Tree Project

City of Frederick, Dept. of Public Works

Clark Nexsen

Colorado Dept. of Agriculture

Connecticut Dept. of Transportation

Dewberry & Davis, LLC

Fairplains Nursery

Home Nursery Inc

International Society of Arboriculture

Jackson & Perkins Wholesale

Kurt Bluemel Inc

Law's Nursery Inc

Lawyer Nursery Inc

National Garden Center Organization

National Landscape Association

North Carolina Department of Transportation

Nursery Supplies Inc

Oakland County MI Dept. of Facilities Management - Grounds Unit

Scarff's Nursery Inc

US National Arboretum

Valley Crest Tree Company

Westenberger Tree Service Inc

Wholesale Nursery Growers of America

Zelenka Nursery Inc

American Standard for Nursery Stock (ANSI Z60.1-2004)

1

plant size, by height or caliper, as appropriate to the plant type.

shall include plant size, by height or caliper, as appropriate to the plant type, and container

class or box size.

and minimum fabric bag size.

Unless otherwise specified, all shade and flowering trees should be single-trunk.

sections, below.

size interval. That size will be the minimum size allowable for that size interval and shall

include plants from that size up to but not including the next larger size interval. Acceptable

size intervals for each plant type are shown in the appropriate plant type sections, below (see

Section 1.2). For instance, a specification for a “2.5 in. cal.” Type 1 shade tree references the

“2.5 to 3 inch” caliper size interval, while a specification for a “5 ft.” Type 4 spreading tree

references the “5-6 ft.” height size interval.

Height measurement shall be taken from ground level for field grown stock and from the soil

line for container grown stock, which should be at or near the top of the root flare.

Caliper measurement of the trunk shall be taken six inches above the ground up to and

including four-inch caliper size. If the caliper at six inches above the ground exceeds four

inches, the caliper should be measured at 12 inches above the ground.

Seldom are tree trunks perfectly round. The most accurate measurement will result from the

use of a diameter tape. Caliper measurements taken with manual or electronic “slot” or

“pincer” type caliper tools should be the average of the smallest and largest measurements.

American Standard for Nursery Stock (ANSI Z60.1-2004)

2

caliper shall take precedence over height if a height measurement is also provided.

height through 7-8’ size interval, then caliper in inches thereafter. Both height and caliper

measurement may be provided for all sizes.

trees, measurement indicates height in feet through 5-6’ size interval, then caliper in inches

thereafter. Both height and caliper measurement may be provided for all sizes.

Nursery stock shipped in accordance with the required specifications shall be deemed to be

acceptable within the terms of this section if it is typical in size and habit for the species in

the region of the country in which it is grown unless specifications include additional details.

Specifiers and buyers are encouraged to provide additional appropriately detailed descriptive

language to the extent that required specifications set forth in Section 1.1.1 do not provide

sufficient detail for a particular transaction.

If only height or caliper shall be specified, both height and caliper may be specified.

In certain landscapes, such as street tree or container plantings with limited soil availability,

or when the buyer desires a particularly well-formed root mass, specifications should include

the minimum number of times that nursery stock shall have been transplanted (e.g., “trans.

3x”) or root pruned. In such cases, nursery stock may be shipped with a root ball smaller

than that shown in Table 6, and the smaller root ball should be specified. Root ball sizes in

Table 6 are based on trees that have not been transplanted after they have been lined out in

the field, which is the typical and accepted practice in the industry.

When “specimen” or “quality grade” trees are called for in landscape specifications, the

desired characteristics shall be stated. Specifications should include deviations from

standard minimums for caliper, height, root ball diameter, container or box size, etc., as well

as other factors such as symmetry, crown width, fullness of branching, single or single

dominant leader, age, specialized pruning techniques, or uniqueness of the plant. The

determination of compliance with the term “specimen” shall be determined with reference to

the descriptive characteristics provided in the specifier’s or buyer’s specifications.

Bid specifications for trees for street plantings shall specify the height to which the tree

should be free of branching. The height of branching specification shall bear a relationship

to the size and kind of tree, so that the crown of the tree is in good balance with the trunk.

American Standard for Nursery Stock (ANSI Z60.1-2004)

3

branched 1 foot or more below the standard height and still provide proper clearance, which

is the purpose of this specification.

FIGURE 1 – Caliper and branching height

Where a certain form of growth is desired which is not in accordance with a natural growth

habit, this form should be so specified.

structure and to develop a more formal effect.

Table 1, below.

It is recognized that climatic conditions in different sections of the country produce trees of

different caliper-height proportions. Trees from one region of the country may have less

caliper in proportion to height while trees from another region may have greater caliper in

proportion to height than shown in the following table. The table below shows the average

height range and the typical maximum heights.

American Standard for Nursery Stock (ANSI Z60.1-2004)

4

½ in. 4 to 5 ft. 6 ft.

5/8 in. 5 to 6 ft. 8 ft.

¾ in. 6 to 8 ft. 10 ft.

1 in. 8 to 10 ft. 11 ft.

1 ¼ in. 8 to 10 ft. 12 ft.

1 ½ in. 10 to 12 ft. 14 ft.

1 ¾ in. 10 to 12 ft. 14 ft.

2 in. 12 to 14 ft. 16 ft.

2 ½ in. 12 to 14 ft. 16 ft.

3 in. 14 to 16 ft. 18 ft.

3 ½ in. 14 to 16 ft. 18 ft.

4 in. 16 to 18 ft. 22 ft.

4 ½ in. 16 to 18 ft. 22 ft.

5 in. 18 ft. and up 26 ft.

American Standard for Nursery Stock (ANSI Z60.1-2004)

5

Caliper measurements shall be 1/8-inch intervals from ½” through ¾”, ¼-inch intervals

through 1¾-2”, then ½-inch intervals through 5½-6”, then one-inch intervals through 9-10”,

then two-inch intervals from 10-12” and up. Decimal equivalents to fractions may be used.

For bare root and container-grown stock only, through 7-8’ size designation, height

measurements shall be in one-foot increments. Thereafter, measurement indicates caliper.

measurement in relation to caliper as in Type 1. The height, however, should not be less than

two-thirds the height relationship given for Type 1 (See Table 1).

FIGURE 2-Measurement-Type 2 shade trees

Caliper measurements shall be ¼-inch intervals through 1¾-2”, then ½-inch intervals

through 5½-6”, then one-inch intervals through 9-10”, then two-inch intervals from 10-12”

and up. Decimal equivalents to fractions may be used.

For bare root and container-grown stock only, through 7-8’ size designation, height

measurements shall be in one-foot increments. Thereafter, measurement indicates caliper.

American Standard for Nursery Stock (ANSI Z60.1-2004)

6

single-trunk plants, as multi-trunk clumps, or as shrubs.

A height relative to caliper may be specified but shall not be considered in determining

minimum diameter ball sizes.

For single-trunk plants, the minimum relationship for height, caliper, and branching will

usually be as shown in Table 2, below.

2 ft. 5/16 in. Three or more

3 ft. 7/16 in. Four or more

4 ft. 9/16 in. Five or more

5 ft. 11/16 in. Six or more

¾ in. Seven or more

FIGURE 3-Type 3 small upright trees

American Standard for Nursery Stock (ANSI Z60.1-2004)

7

Height measurement shall be in one-foot intervals. Height shall be the governing

measurement through 5-6’ interval. Thereafter, caliper takes precedence.

Caliper measurements shall be ¼-inch intervals through 1¾-2”, then ½-inch intervals

through 5½-6”, then one-inch intervals through 9-10”, then two-inch intervals from 10-12”

and up. Decimal equivalents to fractions may be used.

certain large shrubs grown in tree or multi-stem form.

A height relative to caliper may be specified but shall not be considered in determining

minimum diameter ball sizes.

For single-trunk plants, the minimum branching will usually be as shown in Table 3, below.

FIGURE 4-Type 4 small spreading trees

2 ft. Four or more

3 ft. Five or more

4 ft. Seven or more

5 ft. Eight or more

¾ in. Eight or more

American Standard for Nursery Stock (ANSI Z60.1-2004)

8

Height measurement shall be in one-foot intervals. Height shall be the governing

measurement through 5-6’ interval. Thereafter, caliper takes precedence, except for shrubform

multi-stem trees (see section 1.3).

Caliper measurements shall be ¼-inch intervals through 1¾-2”, then ½-inch intervals

through 5½-6”, then one-inch intervals through 9-10”, then two-inch intervals from 10-12”

and up. Decimal equivalents to fractions may be used.

Shrub form, clump form, or multi-stem trees occur naturally in many genera or may be

“Suckers” from trunks or from the roots that have branching or form that are not typical for

the species or cultivar shall not be treated as “stems” or “trunks.”

All specifications shall include whether the form desired is shrub form, clump form, or multistem.

height or caliper, as appropriate to the type, and the method used to determine the caliper

measurement if caliper is required.

This form is determined by the manner in which the plant is maintained, in that generally all

persistent, thriving stems arising from the root crown or at a point just above the root crown

are retained, and foliage is allowed to remain intact on branches close to the ground.

Additional stems may grow from the root crown or at a point just above the root crown and

be allowed to grow to maturity throughout the life of the plant, and older stems may be

pruned to the ground. Also, species in this group generally do not exceed 15 feet in height at

maturity, are generally Type 3 or Type 4 trees, and may naturally produce multiple stems

without manipulation in the nursery.

American Standard for Nursery Stock (ANSI Z60.1-2004)

9

Specifications shall include plant size (height) and shall indicate “shrub form.” See Section

1.1 for additional required specifications. Optional specifications may be included in order

to further describe the plant (See Section 1.1.2).

Measurement shall indicate height, in accordance with Section 1.1.1.2, using the following

intervals: one-foot intervals up to 7-8’ height, then two-foot intervals thereafter. Each

interval includes plants from the minimum plant size up to but not including the next larger

size interval.

This form is determined by the manner in which the plant is maintained, in that only a certain

number of stems or trunks are retained when the plant is young and thereafter maintained as

the plant matures, and foliage is generally removed from the lower portion of the plant. It is

recognized that, in certain regions of the country, some species are generally sold in the trade

as tree forms rather than shrub forms even though they are allowed to retain most of the

lower branches and foliage, but only a limited number of main stems or trunks are retained as

the tree matures. These are generally Type 1 or Type 2 shade trees.

together as a single tree having three or more main stems or trunks. Multiple tree groupings

shall have a unified, well-established root system in order to allow harvest, shipment, and

planting as a single root ball.

crown or at a point just above the root crown.

American Standard for Nursery Stock (ANSI Z60.1-2004)

10

originate from a single main stem at a point no higher than six inches from the ground.

These types are created with specialized techniques rather than as natural to the species (e.g.,

branches are more than six inches from the ground, specify under Section 1.2 and include

“low-branched” specification.

Specifications for clump form trees shall include plant size (height or caliper as appropriate -

see paragraph below), minimum number of stems or trunks, and method of caliper

measurement if a caliper specification is included. A two-stem clump shall be so specified.

Plant size for Types 1 and 2 clump form trees may be specified by height or caliper up to 7-

8’ height, and then should be specified by caliper thereafter. Types 3 and 4 clump form trees

should be specified by height through 5-6’, then by caliper thereafter. Specifications for all

clump form trees may include both caliper and height measurements.

Specifications for multi-stem trees should be specified by height. Optional specifications

may include the minimum number of stems and caliper measurements. A two-stemmed plant

shall be so specified.

If a caliper measurement is included in the specification, the specification shall also include

the method used to determine the caliper measurement, shown below.

Several methods are used in the trade:

A. The number of required trunks and the minimum caliper of each trunk.

B. The number of required trunks and the caliper of only the largest trunk, with all other

required trunks within a certain caliper range of the largest trunk (e.g., by percent or

within two smaller caliper sizes). This is the Canadian method.

C. The number of required trunks, caliper specified is one-half (1/2) of the caliper of up to

the three largest required trunks.

D. The number of required trunks, caliper specified is the average of all required trunks.

American Standard for Nursery Stock (ANSI Z60.1-2004)

11

FIGURE 5 – Multi-stem, clump form, and shrub form trees

In all cases, root ball diameters for shrub form, clump form, or multi-stem trees shall satisfy

the general requirement stated in Section 1.6.1, below, and root ball depths shall be

determined in accordance with Section 1.6.1.1, below.

Minimum root ball diameters for shrub form trees shall be determined by height, in

accordance with Table 4, below.

Minimum root ball diameters for clump form trees shall be determined with reference to

measurement used in the specification, and even if height only is specified (e.g., for Type 1

or 2 Shade Tree).

For clump form trees with more than 12 inches between the center points of any two trunks,

one-half of that distance should be added to the root ball diameter shown in Table 6 to assure

that a sufficient amount of roots around the perimeter of the ball are retained during harvest.

For instance, if two trunks are 14 inches from center to center, seven inches should be added

to the root ball size indicated in Table 6.

A caliper measurement resulting from the application of the formula which falls between a

caliper measurement in Table 6 should use the next larger caliper shown in Table 6 (e.g., 3¾-

inch caliper, round up to 4-inch caliper, requiring a minimum 42-inch root ball).

Minimum root ball diameters for multi-stem trees shall be determined by height, in

accordance with Table 4, even if caliper measurements are included in specifications.

American Standard for Nursery Stock (ANSI Z60.1-2004)

12

Width no more than

½ height at maturity

Width at least

½ height at maturity

4 ft. 14 in. 24 in.

5 ft. 18 in. 28 in.

6 ft. 22 in. 32 in.

7 ft. 26 in. 36 in.

8 ft. 28 in. 40 in.

10 ft. 32 in. 44 in.

12 ft. 38 in. 52 in.

14 ft. 44 in. 60 in.

16 ft. 50 in. 66 in.

18 ft. 60 in. 74 in.

20 ft. 70 in. 80 in.

In size grading palm trees, height shall take precedence. Either of two heights may be

specified: overall height or trunk height.

Overall height is the perpendicular height from the ground, which should be at or near the

top of the root zone, to the top of the arc made by the uppermost arching frond with the tree

standing in natural position.

Trunk height is measured from the ground line, which should be at or near the top of the root

zone, to the base of the heart leaf.

In cases where the root ball or box (container) size is not specified, the minimum root ball

size or box size recommended in this section shall be deemed acceptable (see Table 6 or

Table 7).

American Standard for Nursery Stock (ANSI Z60.1-2004)

13

FIGURE 6 – Palms

devices, such as containers or fabric bags, under favorable growing conditions and which

have received the proper cultural treatment to develop a well-branched root system. After

harvest, the soil is removed from the roots.

All bare root trees shall have a well-branched root system characteristic of the species. The

following table represents the approved minimum root spread for nursery grown shade trees.

½ in. 5 to 6 ft. 12 in.

¾ in. 6 to 8 ft. 16 in.

1 in. 8 to 10 ft. 18 in.

1 ¼ in. 8 to 10 ft. 20 in.

1 ½ in. 10 to 12 ft. 22 in.

1 ¾ in. 10 to 12 ft. 24 in.

2 in. 12 to 14 ft. 28 in.

2 ½ in. 12 to 14 ft. 32 in.

3 in. 14 to 16 ft. 38 in.

American Standard for Nursery Stock (ANSI Z60.1-2004)

14

FIGURE 7 – Measurement - Field grown trees

Trees collected from native stands or established plantings shall be so designated. The spread

of root on bare root collected trees shall be 1/3 greater than the spread of roots shown for

bare root nursery grown trees (Table 5).

Trees collected from wild or native stands may be considered nursery grown when they have

been successfully reestablished in the nursery row and grown under regular nursery cultural

practices for a minimum of two growing seasons and have attained adequate root and top

growth to indicate full recovery from transplanting into the nursery row.

American Standard for Nursery Stock (ANSI Z60.1-2004)

15

The following tables represent the recommended minimum root ball sizes for trees that are

(a) grown in the ground in the nursery without artificial root restriction devices, such as

containers or fabric bags, (b) grown under favorable growing conditions, having received the

proper cultural treatment to develop a well branched root system, and (c) harvested with the

ball of earth in which they are growing remaining intact (e.g., balled and burlapped).

Many factors affect the minimum root ball size. Although minimum ball size is not a

required specification, parties to nursery stock transactions are encouraged to address

minimum ball size in personal communications or specification documents prior to the

transaction. The objective in all nursery stock transactions is for root balls to meet the

following general requirement:

Given the variety of acceptable cultural practices in the industry, the ball sizes set forth in

this section are based on those factors which are objectively observable and measurable: the

height or caliper measurement. Other cultural practices in the nursery, such as transplanting

or root pruning practices or watering techniques, or soil types and local growing conditions,

certainly affect the density of the roots, but are much more difficult to observe and measure

within the context of the Standard.

It is recognized that plants having a coarse or wide-spreading root system because of natural

habit of growth, soil condition, infrequent transplanting practice, or plants that are moved out

of season, would require a root ball larger than the recommended size. It is also recognized

that there may be circumstances where the sizes recommended may be excessive, such as

stock grown in pots or other containers, field plants recently planted out from containers or

with smaller balls, or plants which have been frequently transplanted or root pruned.

For example, if root density is of particular importance to a seller, buyer, or specifier, the

nursery stock may be designated in marketing materials or in specification documents as

being transplanted or root pruned a certain number of times. In such cases, the grower may

American Standard for Nursery Stock (ANSI Z60.1-2004)

16

½ in. 12 in. 2 ft. 10 in.

¾ in. 14 in. 3 ft. 12 in.

1 in. 16 in. 4 ft. 14 in.

1 ¼ in. 18 in. 5 ft. 16 in.

1 ½ in. 20 in. ¾ in. 16 in.

1 ¾ in. 22 in. 1 in. 18 in.

2 in. 24 in. 1 ¼ in. 19 in.

2 ½ in. 28 in. 1 ½ in. 20 in.

3 in. 32 in. 1 ¾ in. 22 in.

3 ½ in. 38 in. 2 in. 24 in.

4 in. 42 in. 2 ½ in. 28 in.

4 ½ in. 48 in. 3 in. 32 in.

5 in. 54 in. 3 ½ in. 38 in.

5 ½ in. 57 in. 4 in. 42 in.

6 in. 60 in. 4 ½ in. 48 in.

7 in. 70 in. 5 in. 54 in.

8 in. 80 in. 5 ½ in. 57 in.

6 in. 60 in.

7 in. 70 in.

8 in. 80 in.

American Standard for Nursery Stock (ANSI Z60.1-2004)

17

Plants dug to the specifications in the following tables should have the trunk or stem of the

plant in the center of the earth ball. A tolerance of 10% of the diameter is the maximum

deviation allowable (See Figure 8). For example: For a tree with a 30-inch root ball, the

center of the trunk at ground level shall be within a circle 13 ½ inches from the outer edge of

the ball.

FIGURE 8 – Example: trunk in center of root ball

begin at the root flare (see Figure 9). Soil above the root flare, from being deeply planted in

the nursery as a young plant, as a result of maintenance practices in the nursery, or added

during harvest, shall not be included in ball depth measurement, and should be removed.

Under certain soil and regional conditions, plants have root systems of proportionately less

depth and greater diameter. These require a more shallow but wider ball to properly

encompass the roots. Conversely, in other soils, and in certain regions, roots develop greater

depth and less spread, requiring an exceptionally deep ball, which may be smaller in

diameter and greater in depth than the size recommended.

For the greater part of the country, ball depths will carry the following ratios:

Balls with diameters less than 20 inches - depth not less than 65% of the diameter of the ball.

Balls with diameters of 20 inches and up - depth not less than 60% of the diameter of the

ball.

American Standard for Nursery Stock (ANSI Z60.1-2004)

18

FIGURE 9 – Measurement of root ball depths

Burlap or other suitable material shall be biodegradable and shall completely cover the root

ball. This wrapping shall be between the earth ball and the lacing or ball supporting device.

If used, ball-supporting devices, such as wire baskets, shall hold the ball in a firm, rigid

condition.

It is generally recognized that plants growing in their native state will sustain a much more

severe shock when transplanted than the same kinds of plants when nursery grown. If

collected material is moved, a considerably larger ball than that recommended for

transplanted nursery stock is required, because of the unrestricted root development and the

varying conditions of soil in which such material is found.

The minimum ball sizes shall be equal to those specified in Table 6 for the next larger size

nursery grown stock.

For the purposes of this Standard, plants collected from wild or native stands may be

considered nursery grown when they have been successfully reestablished in the nursery row

and grown under regular nursery cultural practices for a minimum of two growing seasons

and have attained adequate root and top growth to indicate full recovery from transplanting

into the nursery row.

American Standard for Nursery Stock (ANSI Z60.1-2004)

19

relatively free of stones and foreign matter, but where plants have had a minimum of aftercare.

Plantation grown nursery stock shall be so designated. The minimum ball sizes shall be

equal to those specified in Table 6 for the next larger size nursery grown stock.

Field potted plants are field-grown nursery-grown plants, dug with a ball of earth still intact

in which they are growing, and which, in lieu of burlapping, are placed in a container to

retain the ball unbroken.

The minimum ball sizes shall be equal to those specified in Table 6 for nursery grown stock.

growing medium is mechanically or manually formed around the roots to form a ball.

Table 7 represents the recommended minimum sizes of processed balls for trees processed by

machine or by hand.

All trees shall have been grown under favorable growing conditions, having received the

proper cultural treatment to develop a well branched root system.

½ in. 10 in. 2 ft. 10 in.

¾ in. 10 in. 3 ft. 10 in.

1 in. 12 in. 4 ft. 12 in.

1 ¼ in. 14 in. 5 ft. 12 in.

1 ½ in. 16 in. ¾ in. 12 in.

1 ¾ in. 18 in. 1 in. 14 in.

2 in. 20 in. 1 ¼ in. 14 in.

2 ½ in. 20 in. 1 ½ in. 14 in.

3 in. 28 in. 1 ¾ in. 18 in.

It is recognized that balling of nursery grown stock can be accomplished by hand digging or

by mechanical devices especially designed for nursery conditions. The use of digging

machines is an acceptable nursery practice.

American Standard for Nursery Stock (ANSI Z60.1-2004)

20

guidelines for the appropriate plant type set forth in Section 1.2 - Types of Trees. Plant size

indicates the minimum size allowable in the desired plant size interval. Container size shall

be by container classification (i.e., not by container volume) as set forth in the container class

table in the Foreword.

In all cases, container grown nursery stock shall meet the following general requirement:

It is recognized that certain containers may be designed or treated to retard circling roots

around the inside of the container, and that they are acceptable in the trade.

The container shall be sufficiently rigid to hold the ball shape and to protect the root mass

during shipping.

specification that should be determined after the desired plant size is determined. This table

is to be used as a guideline in determining which container class designation should

accompany the plant size designation. This table should not be used as the basis for rejecting

nursery stock based on the minimum or maximum plant size shown in this table in cases

where a specification only provides a container class designation. In such cases, the parties

should refer to the “general requirement” for all container grown nursery stock (see Section

1.7) to determine whether the root system complies with the Standard.

Identify every row with a plant size range that includes the desired plant size. (3) Specify an

appropriate container class in the right-hand column of a row in which the desired plant size

included as the maximum plant size for a #15 container and would NOT be appropriate. A

2” caliper tree is included as the minimum plant size for a #65 container and would NOT be

appropriate. The appropriate container class would be either a #20, #25, or #45, since the 2”

caliper plant size falls between the minimum and maximum plant sizes in those ranges.

Exceptions to this approach would be for very fast-growing species, in which case the

maximum plant size would be an appropriate reference for determining the container class;

or for very slow-growing or dwarf varieties, in which case the minimum plant size would be

an appropriate reference for determining the container class.

Note: Throughout this Standard, plant size indicates minimum allowable plant size in

desired plant size interval (e.g., “1 in. cal.” specification designates size interval from 1-inch

caliper up to but not including 1 ¼ -inch caliper).

American Standard for Nursery Stock (ANSI Z60.1-2004)

21

Shade Trees

Small Upright and Small

Spreading Trees

Minimum

Plant Size

(Height/