Steve,
I was pleasantly surprised to read your thread. As I am sure you are aware ANSI Z.60 covers many things but it does not cover quality. Sadly most firms have old and outdated specifications on this matter or do not know enough in the first place to know any better. The challenge you will run into is that every portion of the country does things differently from bare root, balled and bur lapped, to primarily containers out here in California and Arizona. There are multiple ways to get to a better root system, root pruning is one such avenue. Although it should come with some disclaimer that the Rosacea family is prone to transmitting crown gaul and the practice of root pruning can spread the disease. Currenlty the Urban Tree Foundation is working with Dr. Ed Gilman, Jim Urban and the ISA to develop a series of specs and details for landscape architects which would assist in specifying better plant quality on the job sites. Unfortunately until we as LA’s begin to have a better understanding and increase our knowledge of plants specifically tops and bottoms the process shall continue as is. On the brighter side the industry is just now beginning to turn its attention to roots and are seeing how large the issue is.
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