1. Do consumers prefer certain plant conditions in the outdoor retail setting?

2. Does the presence of trees influence consumer place perceptions?

3. Does the urban forest have an affect on consumer behavior (e.g. patronage and product pricing)?

Article Reference: Green Plants for Green Buildings

Submitted for the 2002 People/Plant Symposium

Amsterdam, Netherlands

By Kathleen L. Wolf, Ph.D.

Center for Urban Horticulture

University of Washington

Research Approach

Both qualitative interview and quantitative survey methods were employed in the studies. The interview phase was conducted in urban neighborhoods of the Pacific Northwest region of the United States. The survey phase compared business peoples' and consumers' responses. Data was collected in multiple U. S. cities: Seattle (Washington), Portland (Oregon), Austin (Texas), Los Angeles (California), Chicago (Illinois), Pittsburgh (Pennsylvania) and Washington DC.

The research survey evaluated several facets of public response to trees and plants and flowers in retail settings using psychometric and econometric measures. In one section respondents (merchants and residents of nearby neighborhoods) were asked to rate varied streetscape scenes for visual quality. The scenes showed outdoor retail settings with differing amounts and arrangements of vegetation. The survey also contained sections of questions about shopper perceptions of places that have or don't have trees or flowers and plants. Respondents were then asked to express what they were willing to pay for goods in three different retail settings, each having different urban forest conditions. Demographic questions revealed the traits and characteristics of respondents.

Streetscape Preferences

Statistical analysis for visual quality produced five visual categories based on preference ratings of thirty-two images. Comparisons of urban forest category means reveal that categories containing scenes with no vegetation or scattered small plants are valued the least. Meanwhile, larger trees or flowers and plants are associated with higher preference; both open and dense tree canopies are valued.

Finally, categories with the highest visual ratings have multi-layered vegetation and are more ordered. Trees and accessory vegetation are placed and managed to create distinct visual patterns within the streetscape. Differences were noted in how consumers and business people react to the appearance of business settings. Business ratings of districts without trees are higher than visitor ratings, despite the grim, hard-featured character of the street setting. Then, in response to places with trees, business people consistently rated such places lower than visitors. Merchants may have less appreciation for trees than consumers, the people they wish to welcome to their shops.

Place Perceptions

Interviews with merchants and business association staff revealed strong attitudes about the values of  trees and their suitability in the retail environment. These stakeholders shared some perceptions about trees, but differed widely on many issues. Thematic analysis of the interview content generated categories of both tree annoyances and benefits. Costs and annoyance perceptions centered on specific issues or problems that impact business profits. Small businesses with marginal profitability feel unable to extend their operating expenses to curbside. The most frequent complaint about trees is reduced visibility, implying reduced consumer access. Trees are blamed for screening signs, awnings, storefronts, and window displays from both pedestrian and automobile traffic. Engineering impacts are another category of costs. On-site exhibits of structural damage included buckled sidewalks, cracked curbs, and heaved road edges, as well as trees entangled in utility lines.

Merchants described loss of functional space as another annoyance. Trees are perceived to reduce usable outdoor space, particularly parking. A direct cost to businesses is removal of tree debris. Flowers, twigs, fruit and leaves are all materials perceived to dirty sidewalks, parked cars and even pedestrians. Security was the final annoyance category. Perceived threats to personal security of both business customers and staff is a common justification for removal of small trees and shrubs. Rather than attending to tree by tree issues, as with annoyances, benefits reports focused on generalized psychological and perceptual dimensions. Lewis (1996) wrote that "landscaping tells stories and defines settings." Dwyer et al. (1994) report that extensive preference assessments for urban forests have revealed the "deep emotional ties between people and trees," including sensory, symbolic and human community dimensions. Business organization staff, in particular, recognized that powerful messages of trees can be harnessed to create more profitable retail settings.

The first of four benefits categories was Positive Mood. Plants and trees, if properly selected and maintained, create a positive experiential and sensual space. The second category, Visual Identity and Unity is about creating an imaginable, distinctive place through the use of plants. These efforts are often combined with display of local cultural heritage, using murals and window displays. A distinct plant palette can also define the boundaries of the district,encouraging visitors to shop within a specific area.

A Message of Care is the outdoor retail extension of a business' customer service commitment. Nassauer (1995) reports that an image of care enhances visual preference for farm and residential landscapes. This also can apply to business districts. A well-designed and maintained street landscape suggests the level of attention that a consumer can expect from a business. The last benefits category, Signal of Change, is about the visual transformations that occur in revitalizing retail centers. Trees may deliver upbeat messages to prospective customers and potential new businesses. One respondent noted that, "If things look nice . . it sends a message to new businesses; they see it as being proactive."