Restoring Client Experience with the Natural World

By Michael Ross, SITES AP, Assistant Professor, Department of Plant Sciences + School of Landscape Architecture, University of Tennessee

Childhood Wonder and Our Diminished Connection to Nature

As we find our urban and suburban spaces challenged by near continuous growth, our connections to the natural world are strained. The issues of biodiversity and landscape resilience are increasingly in the news. These issues will continue to be exacerbated with shifting climatic conditions and natural disaster patterns. Landscapes that are resilient to drought, wildfire, flooding, and competitive with invasive species pressure will continue to serve their intended roles in the face of these disturbances. Hand-in-hand with resilience is the issue of biodiversity. The need to provide food, cover, nesting, and habitat connectivity are crucial if we are going to continue seeing a robust assemblage of native songbirds in our neighborhoods, parks, and greenways.

Awareness and Desires of Forward-looking Clientele

Fast-forward to today: Many of our residential and commercial landscape clients, especially residential clients with kids and grandkids of their own, have begun to realize that they miss the deeper and more personal connection to the natural world that they experienced in their past. As they explore this gap, new types of clients are seeking ways that designed landscapes can provide potential solutions to some of these challenges. Their parallel interests align with concerns about pollinator health, loss of habitat diversity, and increased urbanization. With these changes comes a growing appreciation for bird and wildlife watching, native plants, and sophisticated design, which have continued to expand development of new avenues for landscape expression. There is a vocal, passionate, and motivated group of residential, corporate, institutional, and rural landowners asking for something different, asking for regenerative, ecologically driven landscapes.

Re-examining the Natural World for Contemporary Design Solutions

Ecologically driven landscapes are those that focus on holistic approaches to meet client’s needs and ecological benefit. Rather than a complete rejection of past landscape practices, ecological landscape design, implementation, and management looks to improve techniques and positive outcomes. Examples of this approach might look at how to increase biodiversity and landscape resilience in a neighborhood park, residential rain garden, or that most difficult of residential spaces, the “hell strip”, which may be more technically called the road verge and is that near-impossible-to-manage space between the sidewalk and street (Fig. 1 a and b).

Figure 1a (Left): Hard to manage road verge (Courtesy of Michael Ross). Figure 1b (Right): Sustainable solution for roadside road verge (Courtesy of Michael Ross)

A Contemporary Design Solution Case Study for the Mid-Southern U.S.

Let’s look at an example of landscape design with sustainability in mind. A residential client is looking for an alternative to their lawn framed by boxwoods. Their site is full sun and they have had poor luck in establishing traditional ornamentals as their soil has issues of compaction and construction fill remaining from when the site was developed. Depending on the severity of the compaction, anywhere from a little to moderate intervention may be necessary. We determine that the nutrient poor construction fill is not likely to be too great of a concern. Based on client interviews and site visits an ecological approach is agreed upon. Given the soil characteristics and the solar aspect, discussions start to center on a mesic prairie-inspired design. The plants utilized for this type of project prefer lean soils, full sun, and are adapted to disturbance. The client has children and would like to attract butterflies, beneficial insects, and songbirds to their yard for the family to observe. Planting choices that include larval host plants, nectar plants, cover plants, food plants, and soil building plants are all discussed.

Hidden Ecosystem Services from the Plants We Pick to Perform: Sporobolus heterolepis

In a mesic prairie inspired design, prairie grasses like prairie dropseed, Sporobolus heterolepis (Fig. 2), will help build soil through the action of their deep root structure, carbon sequestration, erosion prevention, and increased stormwater infiltration. The plants will serve as a foundational plant by providing food for granivorous birds and mammals, cover for wildlife, nest material for birds and native bees. Perhaps one of the best characteristics of a plant like Sporobolus are its kinetic aesthetics; grass blades and seed heads will blow in light breezes and the seed heads are beautiful, especially when backlit.

FIGURE 2: A clump of Sporobolus heterolepis grass within a mixed planting with Nepeta racemosa catmint

Site Preparation and Planning with Plants in Mind Will Pave the Way for Success

The goal in traditional landscape design has been to prepare a planting bed with ample soil amendments, aeration, and then maintain plants with extensive water use and chemical fertilizer and pesticides to keep plants happy and healthy looking. Ironically, while this approach creates the perfect growing condition for a wide range of ornamental plants, doing so also enhances problems from unwanted weeds. Weed species are typically aggressive growers and are among the first plants take advantage of available resources by rapidly completing their lifecycle and getting propagules into the seed bank. In a landscape that is sustainably designed, a preferential choice for plants that are disturbance-adapted and resilient to stressors yields great advantages via reduced landscape maintenance needs. When resilient plants are used and become established in the landscape beds, moderate plant stress can actually become an asset. Seek out plant species that are adapted to relatively nutrient poor soils and that don’t require specific light exposures or oxygen-rich soil conditions. Selection of plants that capably perform in soils with modest nutritional status will also allow the grounds manager to reduce or even eliminate soil amendments. In turn, the weeds will be forced to compete with desirable plants in a more equitable way…and competition between plants becomes a management tool. In these landscapes, horticultural maintenance techniques can be applied selectively, as needed, instead of in a blanket approach and so saves time, effort, and money.

Selecting Companion Plants in a Prospective Portfolio

If Sporobolus forms one of the key foundations of the planting then spring-, summer-, and fall-flowering perennial species can be used to provide aesthetic interest, nectar for insects and hummingbirds, and eventually interesting architecture and seed heads that provide food and cover into winter for songbirds. Again, prairie adapted plants would be a good choice.

Species and cultivars of native Rudbeckia hirta (Fig. 3), Ratibida pinnata, Echinacea purpurea and E. tennesseensis (Fig. 4), and Coreopsis lanceolata (Fig. 5), while all rather short-lived, will self-seed and with proper management continue to have a presence in the planting. Species and cultivars of aster, such as New England aster, Symphyotrichum novae-angliae (Fig. 6)

Figure 3: Rudbeckia hirta (Courtesy of Dr. Andrea Ludwig, UT)

Figure 4: Echinacea tennesseensis (Courtesy of Dr. Andrea Ludwig, UT)

Figure 5: Coreopsis lanceolata (Courtesy of Dr. Andrea Ludwig, UT)

Figure 6: Symphyotrichum novae-angliae (Courtesy of Dr. Andrea Ludwig, UT)

and goldenrod, like Solidago speciosa or S. altissima (Fig. 7). The goldenrod cultivar Solidago ‘Dansolitlem’ Little Lemon ® (Fig. 8), is a smaller clump-forming choice, and perhaps better behaved than wildtype goldenrod. These plants will provide nectar later in the summer and into fall. While goldenrod or butterfly weed, Asclepias incarnata (Fig. 9) or A. tuberosa (Fig. 10), might look rangy or out of place in a traditional ornamental bed, these plants would blend in nicely to the mesic prairie approach described in this example.

Figure 7 (Left): Solidago altissima (Courtesy of Dr. Andrea Ludwig, UT). Figure 8 (Right): Solidago Little Lemon® (Courtesy of Dr. Andrea Ludwig, UT).

Figure 9 (Left): Asclepias incarnata (Courtesy of Dr. Andrea Ludwig, UT). Figure 10 (Right): Asclepias tuberosa with bumblebee (Courtesy of Dr. Andrea Ludwig, UT)

Depending on your location, native plants, including grasses like little bluestem (Schizachyrium scoparium), shrubs like fragrant sumac (Rhus aromatica) and spicebush (Lindera benzoin), and perennial herbs like coral bells (Heuchera spp.) and sedges (Carex spp.; Fig. 11) can serve as reduced maintenance plants that contribute to ecologically meaningful landscapes. The heart of successful sustainable landscape design is closely tied to selection of plants that don’t require inputs in large amounts of time, chemicals, money, maintenance, etc. Plant material that doesn’t require a lot of babysitting frees up the ability to actually enjoy the landscapes that we design.

Figure 11: Carex cherokeensis (Courtesy of Dr. Andrea Ludwig, UT)

In addition to a plant selection criterion for limited maintenance, good choice of plants within a sustainable landscape are those species that provide an enhanced ability to support biodiversity. Plants like fragrant sumac provide berries that are eaten by songbirds, and also serve as larval food hosts for hairstreak and other butterflies, while creating microclimates beneath the plant canopy for other animals.

As all of this occurs, the plant is actively contributing to organic matter enhancement in the soil. Plants that have extensive roots, like fragrant sumac, create conditions in the soil that are conducive to beneficial soil organisms. The exudates of healthy plant roots provide sugars, moisture, and organic matter that are used by mycorrhizae, soil mites, and the tiny predators, like pseudoscorpions, that eat them. In current practice, I and my colleagues are using native plants as key components of biodiversity while using floating treatment wetlands to mitigate storm water runoff and stream quality. The roots that hang down in the water and form the primary phytoremediation strategy also provide cover for fish, amphibian larvae, and aquatic insects. The biofilm that develops on the roots also provides a food source that is actively grazed by all the organisms mentioned above.

The Future Looks Bright for Proactive Landscape Design and Creative Designers

One last point to be made in this example is that with careful plant selection, following an establishment period, these plants typically require little or no irrigation, fertilizer, fungicides, or pesticides. Management involves selective weeding, re-seeding to keep the desired species competing against encroachment from weeds and invasives, minimizing soil disturbance, a yearly cutting back, and an appreciation for change over time.

The ecological landscape approach can work well within more traditional parameters and it does not require an all or nothing commitment. While preference for native plant material is an important component for reasons of ecological food web connections, ornamental species and cultivars are fair game as long as they are not invasive. These approaches can be applied at various scales and in different conditions from forested shade to open meadow.

We in the landscape community, designers, contractors, managers, growers, educators and clients are both benefitting from development trends and left lamenting the loss of connections to living systems. Ecological landscape design, implementation, and management is about building connections and that includes the experiential connections that help people love landscapes and reconnect with nature.

For more information, visit:

https://www.wildflower.org/plants

https://tynnativeplants.wordpress.com

https://tiny.utk.edu/floatingislands

https://www.segrasslands.org

https://extension.tennessee.edu/mastergardener/Pages/default.aspx

If you have additional questions, are interested in undergraduate studies in Sustainable Landscape Design, or would like to know more about the University of Tennessee’s Master of Landscape Architecture degree program, contact Michael Ross at mross28@utk.edu or (865) 974-1606.