Tree Appraisal Tool
INTRODUCTION
The 10th edition of the Guide for Plant Appraisal encourages the formation of a Regional Plant Appraisal Committee (RPAC) to maintain and update regional information providing accurate data to facilitate the use of the Guide.
In light of this, in 2021 the New England Chapter ISA created an RPAC. The RPAC collaborated with authors of the 10th edition as well the University of Massachusetts to create a tool that allows arborists to choose from a database of 150 common landscape trees and shrubs and receive information on each species to assist in the plant appraisal process.
The New England Chapter ISA would like to thank Dr. Brian Kane, and Dr. Bethany Bradley for their contribution of the baseline data used to power this robust plant appraisal tool. Huge thanks to the RPAC Committee Chair, Dan Cathcart, and the ENTIRE RPAC Committee.
The tool returns:
- cost per square inch* of selected plant (To provide a more relevant representation of what is actually sold in the market this figure was determined by averaging the wholesale cost per square inch of all available sizes, varieties and cultivars of the species of nursery stock across several nurseries in the region)
- additional species information about the species to aid in the depreciation of the plant, including insect and pest issues, hardiness zones, growth dimensions and iTree species rating when available.
- Invasiveness – along with prompts to search suitable replacements
*As the Trunk Formula Technique is based on square inches of stem area some assumptions were made to convert evergreens, typically sold by height, to diameter inches. The following chart shows the figures used:
Evergreen Trees |
|
Spec Height |
Approx. Caliper |
5/6' |
.75/1" |
6/7' |
1/1.5" |
7/8' |
1.5/ 2" |
8/10' |
2" - 2.5" |
10/12' |
2.5/3.5" |
12/14' |
3.5/4” |
14/16’ |
4-4.5” |
18/18’ |
4.5-5” |
This tool is designed as an aid only. Certain situations, specific species types and conditions may require the arborist to research appropriate information to complete an appraisal.
This information will be updated as needed by the RPAC as needed or as indicated by the Council on Landscape and Tree Appraisal.