An Evaluation of Tree Descriptions in a Popular Garden Guide

Abstract

Across the United States, tree planting programs are being implemented through new public-private partnerships. Many programs offer neighborhood residents choices among trees from a prepared species list. Confronted with the task, how is the homeowner who lacks training in arboriculture to make an informed choice? One of the most likely strategies is to consult a garden guide. In the western United States, the most probable information resource to be consulted is the Sunset Western Garden Book1 published by the editors of Sunsef magazine (6). First published in 1933, and now in its 5th edition with over 4 million copies in print, this is a generally well-respected garden guide. Because of its prominence, we wanted to learn the degree to which its descriptions of street trees were consistent with information collected from other sources. As part of a larger study of public perceptions of street trees, we had available the ratings of 8 species by tree professionals, householders with the trees planted in front of their homes, and from individuals viewing slides (4). The 8 species were currently planted in Redwood City or Sunnyvale, California, and consisted of the southern magnolia (Magnolia grandiflora), American sweetgum (Liquidambar styraciflua), Chinese pistache (Pistacia chinensis), Australian willow (Geijera parviflora), fern pine (Podocarpus gracilior), Chinese hackberry (Celtis chinensis), American sycamore (Platanus occidentalis), and the Modesto ash (Fraxinus velutina 'Modesto'). These had been selected by the city arborists as species about which they desired additional information about public acceptance. The following research questions were addressed in the present study: 1. To what degree are homeowners able to rate the characteristics of street trees on the basis of the garden guide descriptions with identifying labels removed? 2. Are there consistent patterns of variation among the species in regard to the rated characteristics? 3. To what degree will the ratings made on the basis of the garden guide descriptions agree with ratings made by professionals, householders experienced with the trees, and individuals viewing slides of the same species?