Using Native Species in Urban Landscaping
Here at Strong Towns, we talk about developing cities that function more like rainforests and less like monoculture soybean farms. But what about the literal greenery that we grow in our urban spaces? Today, we’re sharing a guest post from Strong Towns member and urban gardener, Fawn Hoener, to talk about a Strong Towns approach to greening up our towns. - Strong Towns.
It Is Not Just The Trees
Nature is the original chaotic but smart designer. Just as a town growing organically and incrementally is more complex, stronger and more resilient than one designed to completion, landscaping that is diverse and specific to the site is more resilient and requires fewer inputs such as fertilizer, water, herbicides and insecticides. The praises of trees in the urban landscape have been sung here before, and the EPA website notes that trees also sequester carbon, mitigate heat islands, manage storm water. In addition to the trees, we plant shrubs, flowers, grasses. Usually, when we are selecting these plants, we ask ourselves just a couple questions. “Do I like the look of it? Will it grow here?” We should also be asking ourselves, “Does it belong in this ecosystem? What other species does it help or harm?”
Got Milkweed?
Native species garden in the setback outside Missouri Sierra Club. Photo by Fawn Hoener
Pound for pound, insects provide more protein than beef, and 96% of birds in North America feed their young insects and spiders. Virtually all food on earth starts with the energy that plants have converted from the sun, and the 37% of animal species who are herbivorous insects are the next step in a complex food web. Surprisingly, though, 90% of insects are specialists and can digest only one or two species. They will starve without their host plants, as Doug Tallamy explains in his 2007 book Bringing Nature Home. The Monarch butterfly lays its eggs on Milkweed plants, as this is the only species that the larvae can digest. The butterfly American Lady prefers as a host plant Antennaria neglecta, commonly called Pussytoes. The insects and plants have evolved together in complex ecosystems over thousands of years. It is only recently (in the last 300-400 years) that we began using plants from other continents so widely.
The problem with growing alien plants in our urban spaces is that the local insects don’t recognize them as food and can’t digest them. Fewer insects means fewer birds and other species that feed on insects leading to a more sterile environment. And ironically, monoculture leads to more insect pests, as the native predators of the pests may not have habitat.
What is an Urban Gardener to Do?
By taking a Strong Towns approach to landscaping our urban spaces (bottom-up, decentralized, incremental, scalable, adaptable) and selecting plants that evolved in the ecosystem we are gardening in, we increase the diversity of the local fauna as well, by providing them food.
Doing this can reduce gardening expenses, improve quality of life, and slow the rate of extinction of plants and animals.
We Can’t Just Let It Grow Wild
A fall view of the Brightside Native Species Demonstration Garden, a formal garden design using native species. Photo by Jim Diaz.
Planting native species in masses gives a more formal appearance to an area. When designing a garden, gardeners should also pay attention to the size and shape of mature plants, as well as soil conditions, sun exposure, and normal rainfall in the area. Hardscaping such as a stone wall or border around the green area can lend a more formal look to a natural design. Planting in masses makes it easier to identify weeds, which is useful when the maintainers of the garden are less educated about what plants are desired, such as a volunteer work force at a church.
Scott Woodbury, manager of the Whitmire Wildflower Garden at Shaw Nature Reserve in Gray Summit, Missouri, notes that it takes about 4 man hours per week to maintain a 2,000 square foot formal garden and about 2 man hours per week to maintain the same sized garden with a “tossed salad” design.
The cost of labor to maintain greenscaping is only part of the ongoing expense. Other costs can be significantly decreased by using native species. By selecting plants that evolved to be in the conditions they are growing in, the need for watering, herbicides and insecticides is greatly reduced.
Cost Savings
Native Prairie at Alberici Construction, St. Louis, Missouri. Photo courtesy of Alberici Construction.
Alberici Construction in St. Louis, Missouri converted the 3.6 acres landscape at their headquarters from conventional landscaping and lawn to native prairie grasses. The conventional landscape required mowing, trimming, mulching, water, replacement, over-seeding and fertilizing at an annual cost of $67,800. The annual cost for the prairie management, on the other hand, is a mere $14,250. This includes removal of invasive species and trimming near walkways as well a controlled burn of one third of the prairie every 2-3 years.
What do people think about this wild place in the city? Here's John Alberici's answer:
“We have signage to let all who pass our property know the natural prairie look is intended and not the result of neglect. Still, it is, to some people, not the expected business setting. We have a lot of tours, especially when we host community functions at our offices, and we never miss the chance to educate the general public as to the environmental advantages of the prairie. Most people are surprised and appreciative of our efforts, once they understand the strategy. To me, the color, texture, movement and sounds of the prairie are far superior to a managed lawn. We also have bee hives on the property which are thriving, partly as a result of our groundcover choice. Though not the expected or ordinary, it is a good message to send to the community.”
Knowing Better, We Do Better
Newly planted butterfly garden at the St. Louis Quaker meeting house. Photo by Fawn Hoener
Too often, we select our landscape and garden plants because they look pretty or smell good, unmindful of the complex web of relationships that unsupervised ecologies support. As we become more aware of these intricate connections, we can select plants that feed the insects and birds and ultimately us. We can begin to restore the ecosystems we have so badly damaged.
Many cities and towns could reduce maintenance costs for their parks and green spaces by converting their plantings to those native to the area and reducing the need for watering and chemical inputs. Where there are plants that will attract local fauna, the ecological resilience of the community is improved.
Gesturing toward a Monarch butterfly feeding on an aster at the Whitmire Wildflower Garden, Scott Woodbury speaks to supporting the intelligence of living systems, “Having butterflies come through on their migration and providing the fuel that gets them there. Doing something meaningful and beautiful. Who doesn’t want to be a part of that?”
Fawn Hoener is retired from almost 30 years of hospice nursing and is an avid native species gardener, mostly in other people's gardens. She lives in a walkable town that has reinvented itself after years of neglect and is happy to contribute to its revitalization. She blogs about voluntary simplicity at smallhousebiglifeblog.wordpress.com.
For 45 years, this Denver organization has been seeding community, one garden at a time.