By Kim Halyak
This is the second in a series of interviews on designing with native plants for our urban gardens, perfect for getting ready for this year’s garden walk, whose theme is “Cooper Young Goes Native.”
This month’s expert is Chris Cosby. Cosby worked 12 years at the Memphis Botanical Gardens, serving as greenhouse propagator, collection curator, designer of six of the botanic garden’s most cherished themed gardens, garden educator and senior manager of the horticultural staff. He has earned recognition as one of Memphis most cherished thinkers in the art of horticulture. Manager of Horticultural Operations.
Since leaving the botanic garden, Cosby and his wife, Stephanie started the ecological garden design company Plants + People dedicated to crafting inspiring and meaningful spaces that benefit both people and planet.
Tell us a little bit about your occupation and background.
I’ve studied plants in some capacity my entire life, and much of what I’ve learned has come from direct observation and experimentation over many years. I studied anthropology in school, with a focus on ethnobotany, the study of relationships between people and plants, and came to understand that the discipline includes much more than culinary, medicinal, and economic species; it also encompasses all of the relationships between people and landscape.
During my 12 years with Memphis Botanic Garden working as propagator, collection curator, designer, and manager of horticultural operations, I came to understand that horticulture has a role to play in reordering our relationship with plants and landscapes. Horticulture’s most valuable role is to realign the relationship between plants and people — realign it so that it contributes to our understanding of natural systems and allows us to regenerate the grossly degraded landscapes we inhabit.
In the fall of 2016, I left the botanic garden and formed PLANTS + PEOPLE with my wife, Stephanie. We’re a Memphis-based business connecting people to plants through ecological garden design, education, and consultation. We know that meaningful interactions with planted environments can increase quality of life for people and communities, so we’re here to help with that.
When and why did you become interested in native plants?
I grew up hunting and fishing, and it was essential to learn which plants or habitats the game and fish favored in order to be successful. The profound beauty of the fields of broomsedge and aster I hunted quail and rabbits in every autumn made a tremendous and lasting impression on me, and that love of and interest in plants has never diminished. To this day, I find myself observing and cataloguing plants in the various landscapes I visit or pass through, trying to understand the nuances of the relationships between plants and place.
How strict are you on the term native plants? What is your definition of native plants?
For me, it isn’t possible to separate place and time when thinking of species’ nativity. Environmental conditions are constantly in flux, and the species composition of a given area changes naturally along with these conditions. The length of time involved gives the impression of a kind of permanence to a landscape, and thus a notion of nativity. These assemblages of “native” plants are ephemeral phenomena and are, in fact, in a state of perpetual change.
We are currently in the midst of a highly visible and obvious reordering of the global landscape, and it behooves us to understand this process of change and how we can engage with it in intelligent and mutually beneficial ways. Xenophobic rhetoric about “invasive exotics” only serves to impede our understanding of these immigrant plants and the roles they play in the ever-changing landscape.
Why should homeowners include native plants in their gardens?
I suspect that most gardens are already home to native plants, but many are quite unassuming, such as the numerous local Carex species, and we don’t give them a second glance. I encourage people to look closely at their gardens and properties and notice which species call their gardens home.
Each site has a unique set of conditions-sunlight, aspect, slope, type of tree cover, etc.- that are favorable to particular species. Studying these conditions allows the gardener to make informed choices about which native species are suited to their particular site. Simply making room for the species already present is a huge contribution to conservation efforts.
How do you feel about mixing both natives and showy non-native ornamentals in a garden?
The fact is that most areas of concentrated human populations are already inhabited by a mixed bag of species from around the globe, and I feel that the landscape would be poorer for the loss of most of these immigrants. I advocate plantings that are informed by studying natural assemblies of plants in analogous habitats around the world. For example, Virginia bluebells and woodland phlox are quite nice under Asian magnolias, I think, and they mingle well with hellebores and epimediums, both of which hail from Eurasia and are found in forests, woodland edges, and savannahs. The urban landscape closely approximates these kinds of environments, and offers near-infinite possibilities for plant combinations.
The key is in designing a functional landscape, so think in layers and leave off the double-flowered and fancy forms of plants, native or not, to allow the pollinators to make use of them.
What particular native plants stand out as “must haves” for the Mid-South region?
I don’t really have a definitive answer for this question, as so much depends on the site. Some species are very adaptable, while others favor association with particular tree species or require particular aspects to thrive. Open-pollinated, seed-grown Echinacea purpurea would be on my list, though. It grows well on most mid-south soils and will tolerate quite a bit of shade and still flower. The seed from the first spring flowering period also ripens just in time for the arrival of the goldfinches in early summer, and I find they will eat it as readily as they do sunflowers.
What native plants are not recommended for small urban gardens and why?
This question really sheds light on the notion of “invasive.” Many native species can cover a lot of ground, especially when grown on the amended soils of gardens, and will readily crowd out less vigorous species. Pycnanthemum and physostegia come to mind, as do gelsemium, ampelopsis, and bignonia. These species are just too vigorous and too large for most small gardens, requiring constant vigilance and maintenance to keep in check. Favoring clump-forming species is an easy way to keep the garden in balance with minimal effort.
So many people want to grow natives but don’t know where to buy them. What do you recommend?
Unfortunately, most local nurseries offer a very limited selection of native species, and the plants that are offered are often “nativars” — cultivars of native species bred and selected for ornamental, rather than functional attributes. Wild forms of many native plants just don’t sell well, and sales are what drives most nurseries. They will respond to repeated requests for particular plants by lots of customers, though. The problem of source material becomes very apparent at this point, as there just aren’t many propagation nurseries in our region that specialize in native species. Mail-order nurseries are, at present, our best resource. Missouri Wildflowers has a great list, most offerings are regionally appropriate, and they have very reasonable prices.
What is the best way for interested gardeners to reach you?
I can be reached at chris@plantspluspeople.com or via the Contact Us form at www.plantspluspeople.com.