American Standard for Nursery Stock
The purpose of the American Standard for Nursery Stock (Z-60.2) is to provide buyers and sellers of nursery stock with a common terminology to facilitate transactions involving nursery stock.
For instance, the standards establish common techniques for:
- Measuring plants
- Specifying and stating the size of plants
- Determining the proper relationship between height and caliper, or height and width
- Determining whether a root ball or container is large enough for a particular size plant
This guide is a valuable tool to aid in communication about nursery stock products. The Standard is intended for use by professional horticulturists and landscape architects with an understanding of common horticultural terms, plant nomenclature, and plant attributes.
2025 Edition Now Available
The latest version of the American for Nursery Stock Standard is now available.
Operating Procedures
The approved Operating Procedures for AmericanHort can be viewed here.
The 100+ Years of History
Since 1921, the association has been involved in the creation of the standards. The first edition of “Horticultural Standards” was published in 1923. That’s over 100 years ago.
Throughout its history, the standards have been revised and expanded to meet the needs of the green 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—the forerunner of the current American National Standards Institute (ANSI) was published on June 22, 1949.
A major revision occurred from January 2005 through August 2013 creating ANSI Z60.1, which was approved in April 2014.
Between January 2024 and April 2025, another revision took place, producing ANSI Z60.2.
The proposed ANSI Z60.2 revisions were submitted to a “canvass list” comprising members of the horticulture industry, including:
- Nursery stock producers
- Wholesalers
- Installers
- Related government agencies
The members reviewed and provided an endorsement to develop “evidence of industry consensus” to meet ANSI requirements for accredited national standards.
The final canvass ballots showed unanimous approval of the revisions, which were then submitted to ANSI. The current standards were officially approved on April 12, 2025.