Image Courtesy of A&H Architecture
The lake home is an iconic image of Minnesota life. With more than 90,000 miles of shoreline in Minnesota, there are a lot of property owners grappling with the question, “What can I do with my shoreline?” Interestingly, lakeshore properties are often beautifully landscaped around the house, but the shoreline area is often kept as turfgrass to the edge of the water, armored with rip-rap, or else is left as a neglected, weedy area. Because of complex government regulations and the assumption that these areas must otherwise be “restored,” people often cannot conceive how shorelines can be integrated into their property as a garden space. As a result, shoreline plantings represent an under-realized opportunity for property owners to improve their landscaping while minimizing water quality impacts to the lake.
Shoreline restoration – courtesy of Ramsey Washington Metro Watershed District
There is a widespread assumption that the only acceptable shoreline improvement other than rip-rap armoring is native shoreline restoration, but in practice this is only one of many suitable planting design approaches. The Minnesota Department of Natural Resources, many watershed districts, and organizations dedicated to protecting water quality and wildlife have advocated for the restoration approach because of its many benefits. As a vegetative buffer, native restorations stabilize shorelines against wave action, filter sediment and nutrients carried by stormwater runoff, and can provide critical habitat for wildlife. This message has a powerful appeal to those who treasure wildlife and natural resources, but unfortunately this message falls flat with many others for a few important reasons. One major limitation is that native restoration plantings require specialized knowledge to design, establish, and maintain, which limits the ability of many designers and contractors to successfully implement these projects. Also, native shoreline restorations inherently possess a wild aesthetic that does not appeal to everyone. By reimagining the shoreline as a garden space, design alternatives to turfgrass or native plantings emerge that can be adapted to work with the aesthetic sensibilities of a wider range of shoreline property owners. The overarching design objective of shoreline gardens is replace turfgrass with a densely planted vegetative buffer strip that can thrive in the shoreline condition. Beyond that, the design possibilities are endless. Shoreline gardens can be composed of both native and cultivated species, and be thoughtfully designed to add appeal to the shoreline from both the land and water. Like all gardens, they exist on an aesthetic continuum. At one end of the spectrum there are formal gardens and at the other end are more wild or naturalistic plantings. The continuum speaks to the level of human control visibly evident in the planting.
Topiary Shoreline Garden – courtesy of reGEN Land Design
For instance, topiary gardens represent the formal end of the spectrum where the landscape is precisely controlled through the careful manicuring of hedges. This planting style works well on open sites with formal architecture, where a wild garden might look messy and out of place. However, such a planting can still provide the same stormwater treatment and incorporate a carefully framed, but diverse perennial garden.
Conventional Shoreline Garden Planting – courtesy of reGEN Land Design
For those who want formality, simplicity, and color, the shoreline can be planted using garden variety perennials and shrubs such as daylilies and hydrangeas. While these plants may not provide the same habitat benefits that a diverse native garden provides, they will flower profusely and can easily be maintained by anyone regardless of their level of horticultural knowledge.
Native Shoreline Restoration – courtesy of reGEN Land Design
At the other end of the spectrum are more natural gardens, like the native shoreline restoration shown, where the human imposed order is less apparent and the plants are allowed to intermingle, evoking wild nature. A shoreline garden can be planted as a native restoration, with an effort made to restore the aquatic and emergent plant communities as well as the upland species. This approach tends to work best in more undisturbed settings where it will enhance the existing plant communities and blend with the surrounding natural areas. In each case the goal is to design a resilient planting that is able to thrive in its shoreline context, improve biodiversity, and be appreciated and maintained by its human stewards. In the middle of the spectrum is a more balanced approach known as “Enhanced Nature” that characterizes the evolution of garden design for the 21st century.
Evening Island Shoreline Garden – courtesy of reGEN Land Design
Enhanced Nature, a term popularized by the English ecologist and designer James Hitchmough, refers to a planting that values the importance of beauty for human users and recognizes that human created and managed ecosystems can support considerable levels of biodiversity and perform critical ecological services. The Evening Island Shoreline Garden at the Chicago Botanic Garden is an excellent example of an enhanced nature garden. Built upon a backbone of native plant species, the garden incorporates intermingled bands of cultivated native and exotic plant species to add color and contrast to the planting while at the same time increasing biodiversity. The planting is crawling with pollinators and elegantly stabilizes the shoreline. By creating a planting that is beautiful you increase human investment and ultimately create a more sustainable landscape.
The Wildflower Meadows in Olympic Park in London contain species from across the globe -courtesy of The Guardian
Another important aspect of the enhanced nature concept is that rather than focusing on whether a plant is native or exotic, it is more sensible to focus on how its attributes will allow it to thrive within the site context. Given global warming trends, Minnesota is expected to have a climate similar to that of the state of Kansas by 2050. If this is true, then the question of whether a plant is a Minnesota native becomes much less critical than whether a plant can survive periods of intense drought, heat, and flooding. The most critical aspect in plant selection is that the plants are pre-adapted to the conditions of the site requiring minimal inputs of water, fertilizer, and human care. In the case of shorelines, we often want to choose plants that are deep rooted, lower in height and can withstand varying moisture conditions as the lake levels rise and fall. Naturally, when introducing exotic species to shoreline habitats, one must be careful not to plant aggressively seeding species or ones that will naturalize and become invasive. But as our climate becomes more extreme, we will need to carefully design our landscapes by building resilient plantings and soil systems capable of enduring our changing environment. In this way, the future of garden design lies at the intersection of ecology and aesthetics, through the creation of resilient landscapes robust enough to survive in challenging conditions, but beautiful enough to inspire people to protect and maintain them.
This is the premise of our upcoming book, The Lake Minnetonka Guide to Shoreline Gardens. The staff of reGEN Land Design is writing the book with grant support from the Minnehaha Creek Watershed District. The guide is intended to be an inspiring and instructional manual with practical project planning guidance that will empower property owners to improve their shoreline and provide landscape professionals with design resources. By presenting shoreline gardens as a prestigious design feature that will enhance the shore appeal of a property, it is possible to reach a wider audience and catalyze a transformation of our lakeshores. The Lake Minnetonka Guide to Shoreline Gardens will be available for purchase in spring 2015.