The “Desert Oasis” homeowner

The arid southwest of the US has long been a destination point for snowbirds and retirees. Many of these part- or full-time residents enjoy the “desert oasis” aspect of the arid southwest, where nearly anything can be grown if enough water is provided. Thus, lawns and annual flowering plants are a common landscape component in southwestern cities. This landscape aesthetic is increasingly at odds with local agencies and governments, which commonly restrict residential use of water for irrigation and promote water-conserving landscapes as lawn replacements.

Homeowner acceptance of these less traditional, resource-conserving landscapes is variable. Long-time residents in desert communities, such as those in Santa Fe and Phoenix, are less likely to convert to water-conserving (xeric) landscape choices (Larson et al. 2017, St. Hilaire et al. 2010) and the same is true for residents of older neighborhoods in these communities. The desire of long-time residents to retain “desert oasis” landscapes with lush lawns and plantings (mesic landscapes) is both aesthetic and historic. An actual shortage of water was the only reason that many of them would consider landscape changes; environmental concerns, government regulations, and higher water bills were of less importance to these residents (St. Hilaire et al. 2010). In fact, many homeowners in such communities have less grass than they would prefer (Wheeler et al. 2020). Homeowners with these deeply-held aesthetic drivers, surrounded by like-minded neighbors, are resistant to changing their attitudes about landscaping choices.

Research on managing the dual demands of water conservation and landscape choice has focused on arid southwest communities; similar tensions exist wherever water availability is restricted (Morera et al. 2020). Short of strict water-use mandates, overcoming this resistance can be challenging to policy-making bodies.

The “Desert Conscious” homeowner

In contrast to the “desert oasis” homeowners, desert newcomers and residents living in newer neighborhoods are more willing to install xeric landscapes (Larson et al. 2017, St. Hilaire et al. 2010). Their personal aesthetics and desires to conform to social norms are no less strong, but they differ dramatically in their collective views on managing landscapes when water is a limiting factor. They are willing to forgo resource-demanding mesic landscapes for more climate-appropriate plantings.

The “Aspirational” homeowner

In parts of the country where water is not naturally limited by climate, homeowners may be unaware or unconcerned with the environmental costs of their individual yard care decisions (Nielson and Smith 2005). They are, however, concerned about how their neighbors view their landscapes. Living on a wealthy block, or living near others who value lush green lawns, predicts homeowner increases in both water and fertilizer use (Carrico et al. 2018). The homeowners using the greatest amount of fertilizer tend to be in lower wealth categories than others on their block, which suggests an aspirational use of yard care resources (Carrico et al. 2018). These residents may water, fertilize, and apply weed control at more frequent intervals than yard care experts recommend (Nielson and Smith 2005).

The “Land Rich” homeowner

There is a subset of homeowners whose behaviors do not align with previous groups. This group consists of homeowners with larger landscapes. Not only are their behaviors strikingly different, but they are not concerned with what their neighbors think (Visscher et al. 2014). Land rich behaviors are more in line with sustainable landscaping. In general, these “land rich” homeowners:

• Mow less of their land (Visscher et al. 2014).

• Are willing to reduce the amount of lawn on their property (Conrad et al. 2019, Grant et al. 2020).

• Retain more leaf litter on their land (Visscher et al. 2014).

• Are less likely to apply fertilizer and irrigate (Visscher et al. 2014).

• Are more likely to install drought-tolerant landscaping (Grant et al. 2020).

• Plant more trees and have large trees (Visscher et al. 2014).

Aesthetic appeal and the sustainable landscape

A sustainable landscape addresses ecological, and sociological concerns. While there are many ecological and environmental advantages to creating sustainable landscapes, none of these are as important to homeowners as aesthetics. Fortunately, sustainable landscapes can be aesthetically appealing if they are so designed (Khachatryan et al. 2020). A study in Switzerland surveyed homeowner responses to a gradient of garden designs which ranged from “conventional orthodox” (frequent lawn mowing and weeding, intensive use of pesticides and fertilizers) to “ecological unorthodox” (infrequent lawn mowing and weeding, no use of pesticides and fertilizers) (Lindemann-Matthies et al. 2013). The responses to the ecological gardens were decisively positive: these aesthetically pleasing gardens were characterized as “natural” and “species-rich,” while more conventional gardens were described as “boring” and “species-poor.”

The key to achieving an aesthetically appealing, ecologically diverse landscape is highly dependent on design principles: homeowners do not want to see chaos but do want the assemblages of plants to make sense. Lack of an appealing design discourages homeowners from pursing low-input landscapes, even when the separate components of the landscape are preferred (Hayden et al. 2015). When designed and installed correctly, species-diverse landscapes are aesthetically appealing, create plant communities that provide significant environmental services, and provide food and habitat for beneficial wildlife (Chalker-Scott 2018, 2015a, Cubino et al. 2020).

Pathways for compromise

Fortunately, there are alternatives to “all or nothing” approaches to water-conserving landscapes. The goal should be to create opportunities for homeowners to make better decisions in a way that allows them to feel aesthetically fulfilled and accepted by their neighbors. Urban irrigation can often be substantially reduced without compromising aesthetics (Warner et al. 2016):

• Trees and other woody ornamental plants can be added to existing lawn-dominated landscapes, substantially reducing water use and providing other benefits such as shading and wildlife habitat (Bijoor 2021, Conrad et al. 2019, Grant et al. 2020).

• Mixed landscapes (those that contain both lawn and ornamental plants) are overwhelmingly preferred aesthetic choices by homeowners (Khachatryan et al. 2020).

• Low-input, mixed species landscapes have lower maintenance requirements and have economic appeal to homeowners (Khachatryan et al. 2020).

• Lawn species with high water requirements can be replaced with other grass species with lower water demand and high aesthetic value (Hayden et al. 2015).

Alternative water sources

Homeowners are increasingly willing to consider alternative water sources for irrigation purposes. Non-potable water can, within limits, be successfully used for irrigating garden and landscape plants (Botha and Jacobs 2019), particularly when potable water is unavailable due to competing demands. Alternative water sources include air conditioner condensate, recycled/reclaimed water, greywater, and rainwater.

• Air conditioner condensate is a high-quality alternative water source that can be collected and applied to landscape plantings.

• Recycled or reclaimed water is treated effluent from wastewater treatment facilities (Quesnel et al. 2019). While there can be an “ick” factor associated with using recycled water, it is safe to use for irrigation purposes.

• Greywater is water collected from sinks, washing machines, dishwashers, bathtubs, and showers. It does not include toilet water.

• Rainwater can be collected from rooftops and stored in barrels (Chalker-Scott 2017, Jennings et al. 2013). Where lawful, rainwater capture can reduce stormwater runoff, which can be damaging to soils and nearby aquatic systems.

Residents should be cautious when using lower-quality alternative water sources, such as greywater and rainwater. Greywater can contain dissolved salts as well as nutrients, with the former potentially damaging salt-sensitive species (Leinauer et al. 2010). Stored rainwater and low-quality groundwater can house pathogens, algae, and other contaminants; fruits and vegetables irrigated with these lower quality water sources should be rinsed well before consuming (Chalker-Scott 2017, do Espìrito Santo Silva et al. 2020).

Water management strategies in landscapes

There are existing and emerging technologies that can help residents manage irrigation water more effectively. In general, residents are more likely to adopt newer irrigation technologies, such as smart controllers, that are convenient and not management intensive (DeMouche et al. 2007, Fontanier et al. 2017, Khachatryan et al. 2019, Warner et al. 2020b). However, manufacturers of these devices would be wise to consider the wants and needs of homeowners (Zhang and Khachatryan 2019), which will differ depending on an individual's comfort with technology. The most promising development is the inclusion of real-time weather events like rainfall, which allows the smart controller to make irrigation adjustments in response.

Low-tech approaches to water conservation are also available and possibly more effective in increasing homeowner understanding of natural water cycles (Survis and Root 2017) as well as plant responses to environmental conditions. Following are some specific examples of low-tech approaches with substantial knowledge gain:

• Using soil moisture meters to reduce lawn irrigation. These meters were provided by local Extension personnel and highly effective in modifying homeowner behavior (Muntz et al. 2019).

• Consulting historical precipitation mapping as well as current precipitation measurements to inform irrigation use. Master Gardener programs have developed outreach activities to educate homeowners (DeMouche et al. 2007).

• Modifying irrigation time and frequency depending on the landscape type. Xeric landscapes can tolerate small, frequent irrigation events, which saves water compared to mesic landscapes with longer irrigations at a greater depth (Volo et al. 2015).

• Replacing landscape sprinklers with subsurface irrigation, which significantly reduces water loss from droplet evaporation, run-off, leaching, and wind drift (Leinauer et al. 2010). The easiest method of adding subsurface irrigation is the use of drip hoses. These can be installed underneath mulch.

• As reduced irrigation can give weeds and invasive species an advantage over landscape plants (Haeuser et al. 2019), the use of coarse arborist wood chips is highly recommended to suppress weeds while conserving water and benefiting desirable plants (Chalker-Scott 2015b, 2007).

• Using ratchet timers to limit irrigation to set intervals on hose end sprinklers.

Ultimately, the most effective way to deal with residential water conservation is to mandate conservation measures be put in place while residential subdivisions are being planned (Lowry et al. 2011). It is more feasible to require developers to install water-saving technologies in new homes, such as smart irrigation and greywater recycling systems, rather than imposing new regulations on existing home landscapes. Likewise, policies encouraging the substitution of trees, shrubs, and perennials for turfgrass in new residential developments are likely to be more successful than encouraging homeowners to convert existing landscapes to more water-efficient designs.

Soil testing for rational decision making

Researchers increasingly recognize the importance of soil testing before application of fertilizers (Mangiafico et al. 2011, Warner et al. 2018), but few homeowners routinely engage in this practice (Warner et al. 2019b). Without an idea of the current nutrient levels in a landscape soil, it is impossible to know what, if anything, is deficient. Without soil testing it is far too easy to add nutrients that aren't deficient and in doing so create excessive levels of nutrients, some of which have direct, negative effects on plant, soil, and aquatic life.

The benefits of a soil test, performed by a government or university lab⁴ that is equipped to test and interpret residential soil samples, cannot be overstated. For a reasonable fee, homeowners can obtain a wealth of information on their soil health. Specifically, homeowners can discover:

• Levels of all essential macro- and micronutrients, except nitrogen⁵.

• Soil organic matter content (highly variable but can be correlated with nutrient levels).

• Cation exchange capacity (greater than 5 meq per 100 g for nutrient retention).

• Presence of toxic metals of concern (such as lead, arsenic, chromium, etc.).

• Soluble salts (common in arid regions).

• Soil pH.

The most important attributes to look at before adding fertilizer of any sort are the essential nutrients. Any nutrients that are at or above optimal levels should NOT be added. Generally, P and K levels are high in residential landscapes, so “complete” fertilizers (NPK) cannot be used. Homeowners will need to find products that only contain nutrients that are at deficit levels. Often, this means that no fertilizers are needed. More science-based information on managing residential soil fertility has been recently published (Chalker-Scott and Downer 2020).

Kicking the lawn habit

Lawns are not “bad” in and of themselves; they are superior to impervious surfaces in terms of the ecosystem services they provide (Thompson and Kao-Kniffin 2019). Historically poor choices have been made to create unnatural landscapes (i.e., monocultural expanses of grass) requiring constant maintenance to maintain turfgrass quality while preventing other plants (i.e., weeds) from establishing. Such unnatural conditions lead to increased use of water, fertilizer, various pesticides, petroleum, and labor.

Strategies for reducing the footprint of traditional lawns abound and range from individual homeowner actions to strict mandates from policy-making organizations. Homeowner-driven choices would include these types of activities:

• Discontinue the use of potable water for irrigation and replace with recycled/reclaimed water (Leinauer et al. 2010).

• Replace mesic turfgrass species with those requiring less water (Ghimire et al. 2019, Hurd et al. 2006, Leinauer et al. 2010, Wang et al. 2014).

• Replace part or all of lawns with low resource-demanding landscape choices, especially woody plants (Erickson et al. 2008, Hurd et al. 2006).

• Reducing irrigation water loss with the use of smart sensors (Leinauer et al. 2010) or subscribing to notifications of recent rainfall to offset the need to irrigate (Survis and Root 2017).

• Reducing irrigation frequency based on deficit irrigation practices (Fontanier et al. 2017).

• Reducing soil nutrient levels by reducing fertilizer rates and frequency, or by eliminating fertilizer application in favor of mulching mowers (Wang et al. 2014).

Requirements from policy-making organizations, including HOAs and governmental agencies, would include these types of restrictions and subsidies:

• Restrictions on lawn sizes (Conrad et al. 2019).

• Restrictions on fertilizer use during environmentally sensitive periods (Ryan et al. 2019, Thompson and Kao-Kniffin 2019).

• Restrictions on phosphorus fertilizers (Thompson and Kao-Kniffin 2019).

• Restrictions on pesticide applications, especially where children are in contact with turf (Thompson and Kao-Kniffin 2019).

• Restrictions on outdoor irrigation, including increased cost for higher use (Conrad et al. 2019).

• Requirements to use drought-tolerant turfgrass (Conrad et al. 2019, Grant et al. 2020).

• Subsidies or rebates for reducing or replacing lawns (Bijoor 2021, Conrad et al. 2019).

• Subsidies or rebates for upgrading irrigation equipment to high-efficiency systems (Bijoor 2021).

Not surprisingly, residents with existing lawns are most resistant to any mandated activity, with the exception of replacing mesic turfgrass species with drought-tolerant varieties (Conrad et al. 2019). Subsidies and rebates have mixed success depending on the location. Familiarizing homeowners with the aesthetic appeal and ecological value of a well-designed sustainable landscape might convince a subset of them to consider replacing at least some of their turfgrass.

Given the reluctance of many homeowners to remove their existing lawns regardless of the consequences (Wheeler et al. 2020), it is less contentious (and probably more successful) to focus on new residential neighborhoods and implement changes at the development and design stage (Lowry et al. 2011). The green industry can play an active role in these discussions, as they are the best suited for suggesting alternative landscape plantings that will tolerate local conditions.

Leading by example

To become a trusted source of information regarding the need to conserve and protect water resources, the green industry needs to demonstrate its willingness to engage in the environmentally conscious behaviors it wishes consumers to adopt. For instance, there are simple but rational methods for assessing the potential for nutrient runoff; this is important to maintain the economic viability of the nursery and greenhouse industry. By taking part in online courses such as that offered by the University of Maryland, nursery personnel can learn how to create and implement site-specific water and nutrient management plans (Lea-Cox et al. 2004). These credentials will go a long way in reassuring customers that nurseries are truly interested in conservation goals – not just in making a sale.

Becoming mediators in the clash between homeowners and policy makers

Tensions run high as policy-making groups increasingly restrict landscape use of water and fertilizer. The green industry is in the unique position of understanding the need for water conservation efforts and able to provide desirable alternatives to mesic landscape features – especially lawns. Their potential role in civic engagement could be crucial in meeting the landscape needs of homeowners while following local policies (Harlan et al. 2009, Lamm et al. 2018, Ryan et al. 2019).

Providing current, accurate information on landscape design and plant selection

The overriding desire for aesthetically pleasing landscapes is the prime motivator for plant selection decisions. These decisions can clash with policymakers (Lamm et al. 2018), but there is a middle road to be found in making informed plant choices and following sustainable design concepts. This will require a close working relationship with university faculty who specialize in landscape horticulture. Specialists, especially those in Extension, will be able to provide easily understood information that is both science-based and practical. With the presence of Extension faculty at different land-grant institutions, it is possible to collaborate with specialists and thus strengthen the industry-academic collaboration.

These collaborations enable nurseries access to high-quality information they can share in signage, flyers, webpages, and other venues. These resources will reassure homeowners that there are aesthetically pleasing alternatives to lawns that can help reduce the use of natural resources, while allowing nurseries to continue selling landscape plants despite water restrictions (Knuth et al. 2020). Such information can include:

• Lists of plants, both native and nonnative, that are low-input yet attractive landscape additions.

• Tags on pots of plants that are drought tolerant and thus water-conserving (Lamm et al. 2018).

• Actual reductions in water use that would be expected if guidelines were followed (Morera et al. 2020).

• Suggestions, rather than commands, to conserve water by using appropriate plants (Knuth et al. 2020).

• Photographs or displays of environmentally sustainable landscapes that are aesthetically pleasing and realistic for the typical homeowner.

Creating collaborative educational efforts

Once a solid, trusting relationship can be established between the nursery industry and university Extension faculty with relevant expertise, the ability to develop and offer meaningful educational activities to homeowners is possible. As in many states, such collaborations already exist between Master Gardener programs and individual nurseries; these volunteers can effectively be used to collect data, educate the community (DeMouche et al. 2007), and serve as “opinion leaders” who could influence neighbors by demonstrating appropriate practices (Lamm et al. 2018).

Collaborations can go beyond traditional Master Gardener outreach efforts, and homeowners are very receptive to these approaches (Warner et al. 2019b). With the assistance of Extension partners, nurseries could offer a variety of seminars and workshops on topics such as:

• Interpreting soil test results and determining follow-up actions.

• Choosing environmentally friendly fertilizers (Hughes et al. 2012).

• Designing ecologically diverse, wildlife-friendly landscapes.

• Selecting appropriate ornamental plants for specific landscape needs.

• Incorporating scale-appropriate water features and reducing water needs elsewhere.

Identifying audience variety and targeting messages

Given the variety of attitudes about water conservation among homeowners (Chaudhary et al. 2019, Mahler 2019, Warner et al. 2016), it is important to tailor educational outreach efforts to target audiences. To group audiences by common interests, simple surveys could be developed, again with the help of Extension faculty who are practiced in this activity. Such a survey could be conducted passively with flyers at a nursery, or at the end of an introductory workshop or seminar.

Homeowners who realize the benefits of sustainable landscapes and the importance conservation efforts hardly need more encouragement (Chaudhary et al. 2019); instead, they could serve as peer-mentors to help educate neighbors who are not yet convinced of the merits of either. Engaging these latter homeowners might involve introducing them to attractive plant choices that require less water and thus save money. Easy and straightforward actions with tangible results are the best way to encourage unconcerned water users to at least become interested in the topic of water conservation.

Embracing the team approach

For various reasons, green industry professionals and university experts are rarely engaged in cooperative educational efforts. It is imperative that the nursery industry take the lead on breaking down the silos that isolate academics and practitioners because sales of ornamental plants could be reduced if water restrictions prevent consumers from irrigating plants outdoors. Industry groups, such as state nursery and landscape associations, and governmental agencies, such as state departments of agriculture, should provide seed grants for these cooperative relationships to form. There is a dearth of practical, science-based information for homeowners to follow and a collaborative effort between academia and industry would find a vast and interested audience.