Juliet Stromberg is a plant ecologist who specialized in wetland and riparian ecosystems of the American Southwest. Her friends call her Julie and I will presume to do the same. She has retired from her position at Arizona State University, but her husband, Matt Chew, is still teaching ecology from a historical perspective at ASU. He is very much her partner in their 20-year project to restore 4-acres of dead citrus grove and an 80-year old Spanish colonial house, long abandoned and derelict. The property came with water rights, without which their project would not have been possible.
In her recently published book, Bringing Home the Wild: A Riparian Garden in a Southwest City, Julie tells us how she and her partner transformed—with the help of natural processes–this dead patch of land in South Phoenix, Arizona into the oasis that it is today. The first step was to restore the irrigation system, which immediately brought much of the dormant seed bank back to life.
Using the riparian vegetation of the Salt River—the source of their water—as her reference, she chose a half-dozen tree species as the foundation of their garden, such as Fremont cottonwood, Gooding’s willow, and velvet mesquite. Twenty years later, there are now 300 trees, sheltering a community of plants and animals. How did they get there?
The seeds of some trees such as blue elderberry and mulberry were brought from neighboring gardens by birds and small animals. Julie and Matt have seen 157 species of birds in their garden, so we can assume birds have done some of the planting. The seeds of some plants are aerodynamically shaped and were blown in by the wind, adding to the diversity of the garden.
Many of the trees are American in origin, but others are not. Regardless of the method of dispersal, most introductions are welcome in Julie’s garden. She spares her readers the tedious recitation of which plants are considered native and which are not. The Southwestern desert is not an ecosystem with which I am familiar. I was glad to have a tour of Julie’s garden without irrelevant information about the nationality of every plant. For the same reason, I like to travel in distant places where I can’t distinguish natives from non-natives. Everything looks great to me and nothing brings me down more than a guide who wants to inform us of what “belongs” and what doesn’t.
Julie and Matt also planted a fruit orchard and a vegetable garden that bring more birds, insects, and animals to the garden as well as providing food for their table. Eating the fruits of our labors in the garden deepens our respect for what plants do for us and establishes our working relationship with the land.
Managing a wild garden
In keeping with Julie’s opinion that ecological restoration is a form of “glorified gardening,” she actively manages her garden. A few plants that annoy members of her community of plants and animals—such as puncture vine and tumbleweed—are not welcome.
When the delicate balance between predator and prey becomes unbalanced, some protective measures are necessary. If coyotes and dogs can’t keep up with the rabbit population, it’s sometimes necessary to put vulnerable plants into cages to protect them. The root balls of some plants are covered in wire mesh to protect them from hungry gophers.
Plants also assist in their own defense. Where mesquite is grazed by cattle, the tree responds by growing longer thorns to repel the cattle. When plants are attacked by plant-eating insects, some emit a toxin to render themselves inedible. The scent of the chemical wafts to neighboring plants, alerting them to the arrival of predators. These natural defenses are an important line of scientific inquiry that has potential to substitute nature-based solutions for synthetic chemicals.
The population of roof rats in Julie’s home is kept in check with liquid birth control, lest they chew on electrical wires or build nests in car engines.
Gardening with the help of friends
Julie’s is not a manicured garden, but it requires constant pruning to keep trails clear and provide light and space for plants to thrive. The annual scouring of the flood plain by spring floods is one of the natural processes that Julie and Matt could not use to restore their land because irrigation water is channelized and confined by concrete. Julie has come to appreciate the flies and other insects who are the decomposing crew, helping to reduce the accumulation of debris in the absence of annual scouring floods. Sixty-six species of flies assist with decomposition as well as pollination in Julie’s garden.
Julie is happy to have coyotes in her garden, but her dogs disagree. Violent and fatal confrontations between these closely related species required building a wall that confines dogs close to the house at night, while coyotes safely roam most of the garden.
Dogs are an important part of Julie and Matt’s life. Early in the book’s introduction Julie warns readers that they should put her book down “NOW!” if they don’t want to hear dog stories. Julie has walked thousands of dogs in a nearby animal shelter. In addition to her own 4 dogs, there are also occasional foster dogs who need to recover from traumatic experiences to be adoptable. In Julie’s refuge, these traumatized dogs learn to trust again.
Peaceful co-existence
Julie is a recovering academic scientist. Before she retired, she felt that her focus on the accumulation of data needed for scientific analysis was causing her to lose track of the big picture. She needed to stop and smell the flowers, so to speak.
She received her graduate education during the heyday of invasion biology. Julie slowly shifted away from native purism based on her experiences in the field. She has rejected that doctrine, and regrets teaching her students to fear “those who came from somewhere else.”
Julie has a vivid memory of the first step she took on that journey to her gardening ethic of peaceful coexistence. She had been instructed to pull tree tobacco from land along the Salt River that was being restored. The nicotine in the plant was making her feel sick, which seemed to bring her to her senses. She began to wonder what she was doing, “following orders to kill creatures she barely knew.”
Part of Julie’s skepticism about such eradication projects is based on her understanding of how little we know. She realizes that the harm done by non-native species is exaggerated and their benefits are underestimated. Given the limits of our knowledge, we should be obligated to give introduced plants the benefit of the doubt before killing them. She now appreciates the beauty of tree tobacco, which also feeds birds, fixes carbon, and stabilizes the soil. Its seeds were naturally dispersed to Julie’s garden and tree tobacco is welcome there.
Imperatives imposed by climate change
Julie says, “The preoccupation with provenance diverts conservationists and gardeners from critical issues,” such as climate change, food security, and extinction (which, studies show, are not caused by introduced plants). Living in the Southwest, Julie has a front row seat on climate change. It’s always (within the context of our lifetime) been hot there, but now it is blisteringly hot during summer months. She watches hummingbirds in her garden seek shelter in the shade, close to the irrigation drip. She watches dogs panting, birds gasping for breath and plants wither and die in the heat. And she knows that both native and non-native plants store carbon that would otherwise contribute to greenhouse gases causing climate change. Carbon storage varies according to certain plant characteristics, but those characteristics are unrelated to the nationality of plants.
Those who insist on replicating the landscape that existed 200-400 years ago in America are depriving nature of the evolutionary opportunities that will enable survival. We don’t know what life will be capable of living in the climate of the near-future. Nature needs as many alternatives as possible to find the species that can survive. Plants and animals are blameless in this struggle of survival of the fittest. The least we can do is to get out of their way as natural selection finds the life that is adapted to the current and future climate.
Showing respect for nature
Julie does not use any pesticides in her garden….no herbicides, fungicide, or insecticide. She is concerned about the pesticides used by her neighbor across the road who grows cotton. She notices the blue cotton seeds scattered on the ground and surmises that they were coated in insecticide or herbicide that will infuse pesticide into the plant as it grows. The poisoned seed can kill seed-eating birds and other animals and the plant itself will be poisonous as it grows. The dust from the cotton field blows into her property when the field is plowed and after the cotton is harvested because no cover crops are grown to tamp down the dust and prevent the loss of carbon stored in the soil. Julie can see firsthand the damage caused by industrial agriculture and is confirmed in her commitment to avoid using pesticides.
Julie shows her respect for everything living in her garden by her choice of pronouns to describe them: “who” not “what,” “she/her” not “it.” She asks her readers to show the same respect for plants and animals, regardless of their nationality. Avoiding the use of pesticides in our gardens is another way to show our respect for the plants and animals on which we depend, with the added benefit of not poisoning ourselves.
Thank you, Juliet Stromberg, for telling us about your garden and congratulations for what you have accomplished and learned from the experience of nurturing it back to life with the help of nature.
Conservation Sense and Nonsense 