Willingness-to-pay Comparisons for Flats of Groundcover Plants in Plantable Containers: Consumers versus Commercial Buyers in Kentucky

Increasing demand for groundcover plants and increasing consumer preference for more sustainable products encourage nursery crop producers and landscape management companies to assess efficiency and sustainable practices. Ajuga reptans ‘Bronze Beauty’ and Sedum kamtschaticum ‘Variegatum’ were grown in standard plastic containers or plantable containers (Ellepot and SoilWrap) and 12or 18-count flats. These production alternatives were presented in personal surveys of commercial industry personnel and consumers to determine their willingness to pay for these attributes. A conjoint analysis revealed an affinity for both groups to purchase flats of groundcovers and preferred sedum over ajuga. Commercial buyers from larger companies were more likely to purchase plantable containers than those from smaller firms. Generally, flats of Ellepots were preferred over flats of SoilWraps and 18-count over 12-count flats by commercial buyers. Price had a negative impact on consumer willingness to pay. Consumers revealed no specific preference for the plantable containers, although preference for plastic containers declined with age and presence of children at home. Groundcover plants are in demand for residential and commercial landscapes as a result of the aesthetic appeal of masses of these low-growing plants, low maintenance requirement, enhanced environmental impact by reducing storm water runoff velocity, and controlling weeds in landscapes (Klett and Wilson, 2009). Nambuthiri and Ingram (2014) reported that commonly marketed groundcover plants in Kentucky, ‘Bronze Beauty’ ajuga (Ajuga reptans), ‘Herman’s Pride’ lamiastrum (Lamiastrum galeobdolon), ‘Beacon Silver’ lamium (Lamium maculatum), ‘Immergrunchen’ sedum (Sedum hybridum), ‘Red Carpet Stonecrop’ sedum (Sedum spurium), and ‘Vera Jameson’ sedum (Sedum telephium), could be grown to a marketable size from 3.8-cm plugs in 8 weeks in Lexington, KY. Plant quality and growth rates for these plants were similar in two plantable containers (Ellepot and SoilWrap) and a standard plastic container and established well in the landscape. The plantable containers also required 20% less time to transplant into the landscape and reduced the requirement for plastic recycling or disposal. A study of the willingness of U.S. floral crop growers to adopt practices perceived to bemore sustainable revealed that although growers had positive attitudes toward sustainable practices, their adoption was tempered by concerns of implementation and perceived risks (Hall et al., 2009). Consumer perceptions of ecoor environmentally friendly products are diverse (Gladwin et al., 1995; Purser et al., 1995) but consumer demand for product stewardship or environmentally conscious products and business practices is increasing (Dennis et al., 2010; Rihn et al., 2011). Ottman (1998) reported that customers were most interested in already existing ordinary products compared with more green products as a result of price, past performance, or product ignorance or disbelief. On average, the 535 consumers surveyed in Texas, Michigan, Minnesota, and Indiana liked rice hull pots followed by straw containers compared with standard containers (Hall et al., 2010). Approximately one-third of those surveyedwere indifferent to container type. Yue et al. (2010) used auction data to determine that consumers representative of the U.S. population had a positive willingness to pay for floral crops in several different biodegradable containers compared with standard plastic containers. However, the degree of that willingness to pay varied with specific biodegradable container. Yue et al. (2011) found through an Internet survey that consumers in Indiana, Michigan, Minnesota, and Texas were interested in plants being locally grown and produced in more sustainable containers. Biodegradable and compostable containers were more desirable than recycled containers. This study also reported that sociodemographic characteristics of study participants affected their preference for plants. For example, individuals interested in purchasing organic food were most interested in organically produced plants. Another conjoint analysis of survey results revealed that U.S. and Canadian consumer intentions were most affected by plant type followed by origin of production and container type (Behe et al., 2013). A web-based study focused in Texas to determine consumer preference for attributes of container gardens revealed that the relative importance decreased from price (71%) to amount of care information (23%) to color harmony (6%) (Mason et al., 2008). The participants’ preferred price point was $24.99 and desired care information and complementary color harmony. Khachatryan et al. (2014a) showed through a mixed-ordered probit model from an online survey that consumers were willing to pay a premium for non-plastic or plantable containers. Similar results were found from plant auction experiments conducted in the United States and Canada (Khachatryan et al., 2014b). A study that examined determinants of consumer expenditure shares for bedding plants specifically noted higher relative expenditures for younger, higher income, higher educated, white consumers who had lived longer in their current residence (Jin et al., 2013). Two years of research determined that plantable containers were suitable for production of groundcover plants and their establishment in the Kentucky landscape (Nambuthiri and Ingram, 2014). The next step in this project was to determine the acceptance of two common groundcover plants grown in plastic and plantable containers by commercial installers and consumers shopping at an independent garden center. Traditionally, these buyer groups have quite different buying patterns. Commercial installers would be expected to purchase in bulk, look for volume discounts, and have a view toward providing an installation service, whereas garden center consumers would be more likely to be purchasing in smaller lots for home installation. A conjointtype survey was designed to determine their willingness to pay for alternative container technologies, plant type, and flat size. Plantable characteristics of containers typically have inherent credence dimensions; the value contained in the product may not be Received for publication 23 Oct. 2014. Accepted for publication 23 Jan. 2015. This research was funded in part by a Kentucky Specialty Crop Block Grant. Professor. Postdoctoral Scholar. To whom reprint requests should be addressed; e-mail dingram@uky.edu. 408 HORTSCIENCE VOL. 50(3) MARCH 2015 immediately obvious to the buyer. The approach of conjoint analysis has been widely applied in cases in which there are credence attributes to elicit respondents’ stated choice behavior (Carlsson et al., 2007; Hu et al., 2005; Johnston and Duke, 2007). Materials and Methods Ajuga reptans ‘Bronze Beauty’ and Sedum kamtschaticum ‘Variegatum’ plugs from 72-count flats ( 1.5-inch-diameter cells) were supplied by Emerald Coast Growers (Pensacola, FL) and were transplanted into one of three test containers in 12or 18-count flats on 17 June 2013 in Lexington, KY. Containers tested were standard 76-mm round plastic containers (300 cm volume), 90-mm paper containers (570 cm volume Ellepot; Ellegaard A/S, Storstrømsvej 55, Denmark; supplied by The Blackmore Co., Belleville, MI), or 80-mm bioplastic containers (SoilWrap; 330-cm volume; Ball Horticultural Company, Chicago, IL). Each species was transplanted to 10 flats of each container type and flat size. Selection of test plants and containers was based on a 2-year study evaluating plant production and establishment criteria (Nambuthiri and Ingram, 2014). Plants were fertigated weekly or when the electrical conductivity of a pour-through extraction fell below 1.0 dS·M with 200 mg·L nitrogen solution from Peters Excel (21N– 2.2P–16.6K) (Everris, Dublin, OH) and grown in a Quonset-style, white plastic-covered greenhouse with sidewalls and ends removed for ventilation. Plants were observed daily and hand-watered as required. Plants grown in these treatment containers and flat sizes were used as examples in the in-person survey of consumers and commercial nursery/landscape industry personnel to determine their willingness to pay for features of the treatments. Two buyer populations (commercial buyers and consumers) were identified as potentially valuing alternative containers for groundcover plants. Separate surveys were developed to elicit willingness to pay (WTP) from these distinct buyer populations in Kentucky with a view toward comparing valuation of various attributes. The WTP evaluation would help determine marginal values these groups placed on containers that would be associated with various ecologically friendly packaging and lower time of installation. Point-of-survey information was provided in a poster that indicated relative installation times and other container benefits. These buyer populations traditionally approach groundcover purchases differently; commercial buyers inclined to buy in bulk and consumers were more inclined to buy smaller lots in retail settings. Two plant types were introduced as variables to increase the robustness of the marginal effects of container type and flat size. Different bundles of products and packaging size may be sold at different prices. Consumer WTP for each type of product (and each attribute associated) is expected to vary across individuals. The range of prices used in the conjoint experiment should be wide enough to cover the potential WTP (Hanemann and Kanninen, 1999). Before the implementation of the survey, careful market evaluation and pre-testing with commercial garden centers were conducted to ensure both lower and higher end possible prices were included. A total of three price levels were used to maintain the balanced statistical property of the conjoint experiment while maintaining simplicity (Louviere et al., 2000). Several other studies adopted