A Quick Look at the Revised American Standard for Nursery Stock

By Savannah Rainey

When buying and selling nursery stock, both customers and producers should be aware of industry standards and terms so that everyone winds up with the healthy, growing plants they want.

Nurseries first began following national standards in 1923 to help determine how plants should be measured, how to properly assess the health of a plant and how to properly care and house growing plants, among other uses.

But sometimes standards become outdated or need revision. That’s why, beginning in 2005, AmericanHort’s Horticultural Standards Committee spent nine years developing an updated version of national standards. A canvass list of horticulture associations, societies and experts approved the revisions last year. The new standards, titled American Standard for Nursery Stock (ANSI Z60.1), can downloaded for free here.

The revised guide aims to be clearer and easier to use by organizing information in tables to improve readability, adding a new “General Standards” section that lists requirements for nursery stock, clarifying measurement methods, and recognizing alternative container materials.

“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,” AmericanHort states on its website. “This book is a communication tool.”

According to AmericanHort, the top 5 most important revisions found in the guide are:

1. The addition of new tables listing plant sizes, minimum root ball size, cane and branch numbers, various measurement ratios and other information for each plant type.


2. Minimum requirements for nursery stock Type 1 and Type 2 shade trees, which standards say should not have co-dominate stems in the bottom half of the crown.



3. Clarification on how to properly measure caliper.


4. Changes to specifications for in-ground fabric bags and their application.

5. Recognition of fabric as an acceptable container material for encouraging or manipulating root growth.