by Rebecca Lindenmeyr
Thanks to the pioneering work of E.O. Wilson, Doug Tallamy, Jonathan Foley, Marla Spivak and many others, the public has begun to accept the need for native plants in the landscape in order to help increase biodiversity and protect pollinators. It turns out that people really do like nature and are willing to change their habitats if the payoff is more birds, bees, butterflies, and wildlife in general. As ecological landscape designers and installers, we are lucky to be on the front lines and in positions that would allow us to help our clients restore habitats and reduce the spread of invasive species on over half the acreage in the lower 48 States, which is the total area currently in suburban/urban use. That’s enormous positive potential.
One of the most successful strategies in this conversion has been to dispel the myth that landscapes with native plants are messy, a word that strikes terror in the heart of even the most eco-minded homeowner. The ‘messy’ roadblock is not to be underestimated. I’ve found it trumps concerns over budget, space, and time combined. As designers, we know what our clients really want: tidy, low-maintenance gardens, full of color year-round. So we give it to them with orderly, predictable designs with simple clean lines, repetition, and symmetry. We replace neatly clipped exotics with their native stunt doubles and include all the other features that distinguish them as ecological landscapes.
Accepting the Messy to Gain Biodiversity…
Personally, I love the Eco-Contemporary landscape architectural style found in the works of Bernard Trainor, Nelson Byrd Woltz, Reed Hilderbrand, and Oehme van Sweden, and I’m not alone. These modern native landscapes certainly are a huge improvement over their exotic and biologically barren predecessors, but I fear that applied exclusively to an entire property the style may be too simplified to provide the complexity we need to avert the biodiversity crisis. I think that the next step in our progression will be to convince clients to accept a side order of messy with their main entree of eco-neat-and-tidy. The reason lies in our developing understanding of how ecosystems function, and more importantly our realization of just how little we know.
Peter de Ruiter at Utrecht University in the Netherlands (Energetic Food Webs) proposes that ecosystems are like a Jenga tower and individual species are like individual blocks. The role each block plays in the stability of a given tower is relative and constantly changing. All species have the potential to collapse or save the whole, depending upon the circumstances. So in order to support and protect an ecosystem (that in turn supports humans) we need to consider it as an integrated and energetic system and look at how we can protect dynamic relationships both in large ecosystems and in smaller backyard habitats. Since we have only discovered 15% of all species on Earth, I think we should assume there’s something vital going on with the other 85% that’s holding it all together, and aim to protect the whole, not just the few we think are pretty.
The challenge of understanding and reproducing a functioning small ecosystem is made more difficult with rapid climate change. Nothing behaves as it used to. In the Northeast we are seeing warmer temperatures, increased precipitation, reduction of snow cover, more frequent freeze-thaws, and an increase in insect and fungal infestations. In response, our landscape designs will need to spring from our best knowledge of the local natural plant communities that existed before human intervention and then will need to be padded with enough diversity and protection from invasives to give plants and animals the best chance to adapt to change. The more diverse the system, the more resilient it will be.
But how many plant species does it take to build a diverse system? As ecological designers this is a question we debate all the time when creating a new landscape along with which species should be chosen, which cultivars are close enough to the parent, how many different species should we use, and how many plants per species. We also debate how those selections should be arranged. Should they be separated or mixed? What density is necessary for optimal effect? Linden L.A.N.D. Group’s most recent meadow project contained over 4,000 plants and 19 species. Is it better and more full of life than a lawn? Absolutely. Does it act as a visual transition between the formal space and the wild areas around it? Yes. Does it begin to replicate the ecosystem service of the native wet meadow across the street? I doubt it. How complex does the re-created system need to be in order to be effective? And who am I to judge what “effective” is?
Preserving the Wild with Hedgerows
Travis Beck’s recent textbook Principles of Ecological Landscape Design is a thorough guide for translating ecology into design principles and will help both professionals and students answer some of these questions, but in the meantime I think we need to hedge our bets, literally. We need to preserve wild slices on the outskirts of our designs. We need these messy slices teeming with mysterious, integrated, and dynamic relationships because they might contain the stabilizing species that hold the Jenga Tower upright, and those stabilizing species might not be the 20 that we find attractive enough to include in a client’s foundation planting.
Within the multitude of American developments where there are no wild areas left to preserve, we need to try to re-create them as best we can using Beck’s Principles, and then accept that these areas have a life of their own beyond our need for a controlled aesthetic. I’m not under the illusion that hedgerows alone will begin to replace the habitat that has been lost or that they will mimic the dynamics of large-scale climax ecosystems, but incorporating them into 50% of the acreage of the lower 48 states is probably a step in the right direction.
Hedgerows can be designed as microcosms of the natural plant communities that existed in a given area before human interference. They represent diverse and complex woodland margins with trees, shrubs, forbs, grasses, and sedges, enhanced with wildflower species that provide vital pollinator habitat. Once a hedgerow is established, other native species are likely to introduce themselves and increase the complexity and resiliency of the habitat. The difficulty of course is the unwanted guests: invasive species that take advantage of the abundant sunshine and disturbed soils. Maintenance plans are a necessity to control vines and shrubs problematic in each area. Admittedly maintenance would be no small task, but worth the benefits that these hedgerows would provide. The Department of Agriculture’s Natural Resources Conservation Service (USDA NRCS) has done a lot of work re-introducing hedgerows between farm fields, and I think their pollinator hedgerow program could be used as a model in a residential context.
Adjusting the Aesthetic
The side-order of messy might still be aesthetically hard for clients to swallow. Even in my own yard I find this challenging despite my knowledge of its scientific benefit (I have to make an effort to let go in more ways than one), and it is this type of emotional counseling we will need to provide our clients for the concept to succeed. We increase our chances of success by positioning hedgerows out of peer-pressure view, relegating them to the back and sides of our clients’ yards. Luckily, there’s something about the word ‘hedgerow’ that most people find acceptable. It conjures up romantic images of the respectable British countryside and placidly grazing sheep. Further acceptance will come through research and education, trust and patience, and eventually through a shift in our collective aesthetic.
By including hedgerows we continue our mission of creating “cooperative landscapes” that contain both intentionally designed areas and wild areas – some for us and some for them. While observing these wild areas on our land, I have begun to develop what I would call Ecological Faith, as well as a good dose of humility and occasional designer’s block to boot. We’re doing the best we know how, restoring habitats in backyards, integrating science with aesthetics, ecology with design; but there’s so much more to learn, so many species and relationships to discover. As an industry I hope we can work together to save room for the mysteries in our landscape designs – and we can call them hedgerows.
About the Author
Rebecca Lindenmeyr is co-Principal of Linden L.A.N.D. Group, an ecological landscape design/build firm servicing the Burlington area of VT. Rebecca spent nine years working as a consultant to the EPA and the Vermont Agency of Natural Resources before transitioning into her career as a landscape designer. She is a VT Certified Horticulturalist and has served as President of the Vermont Nursery and Landscape Association. Linden L.A.N.D. Group specializes in Northeastern native plants, meadows, green roofs and green walls, invasive species removal, and the creation of outdoor living spaces that pair beauty with function. Rebecca may be reached through her website: www.lindenlandgroup.com.