Weeding Yellowstone

4,022 total words    

16 minutes of reading

“For the earth to stay in balance, for the gifts to continue to flow, we must give back in equal measure for what we take.”

—Robin Wall Kimmerer

On my sixtieth birthday, I was in Yellowstone National Park, crouched in the shade of a gnarled Big Sagebrush shrub taller than I was, preparing to free it from an infestation of houndstongue, an invasive weed from Europe. Houndstongue, a relative of the herb comfrey, can be deadly to elk and other grazers: the plant’s large and enticing oval leaves green up early, but are poisonous, chock-full of an alkaloid that causes liver failure. The species is also a space-hog, crowding out the native bunchgrasses and wildflowers whose interrelationships weave the living fabric of these landscapes. This weed is like the overly enthusiastic new neighbor who, with abandon, proceeds to destroy the community.

I thrust the blade of my plant knife into the clayey soil to pry out the first clump. The sun beat on my back. A trickle of sweat ran under my official polyester volunteer shirt. I grunted and pushed down for more leverage. Suddenly the whole plant, two-foot-long taproot and all, popped out of the ground. I fell backwards. As my butt hit the dirt, I saw the pattern of my life re-form like kaleidoscope pieces reassembling. This is my place, and this is my work.

Weeding Houndstongue

I am a plant ecologist who evolved into a writer telling the stories of this living Earth. While I may have traded a science career for spinning words, I never gave up practicing field ecology. My “hobby” is quietly restoring blighted patches of ground: I weed out invasive plants, seed or plug in natives, and restore sinuosity to creek channels, all in service of healing the land and we who share it. I’ve restored wildlife habitat at a coal-fired power plant, re-prairied gritty industrial sites, and revived a channelized, trash-filled urban creek for trout. That hot day in Yellowstone I recognized that my restoration work had brought me home to a place and a purpose. At sixty, I had been widowed for five years after my husband and the love of my life died of brain cancer. I was searching for a passion and direction to guide my unasked-for solo life. I found it in Yellowstone’s sagebrush country, plant knife in hand.

The place: Yellowstone National Park, almost 3,500 square miles of craggy mountains, volcanic plateaus, and wildly colored canyons; plus world-renowned lakes, waterfalls, steaming hot springs, belching mudpots, and spouting geysers. Our nation’s first National Park, a worldwide symbol of wildness visited by more than 4 million people every year. I work near Mammoth Hot Springs in the northern range, a short hike from the stream of vehicles and visitors, but out of sight, immersed in the community of this wild, untamed land.

Last year, a grizzly bear sow raised twin cubs just uphill from one of my weeding sites, and a trio of pronghorn bucks watched me work, now and again blowing breathy alarm snorts at approaching hikers. One morning while I was resting, a vole, all chunky gray fur and short tail, ran right over my dusty boots, followed closely by a weasel in summer-brown pelage. While I was still collecting my astonishment, the weasel caught the vole and crunched into the creature’s skull, all the while watching me warily with black eyes. If the foot-long predator had been my size, I thought with a shiver, I would have been lunch instead. On reflection, I wouldn’t actually mind ending my life as part of Yellowstone’s food web. It’s a kind of going to ground that seems fitting.

The work: Radical weeding, a plant knife dug into earth, a small but significant act to ameliorate the ecosystem ills of global climate change. I dig, sweat, and pull invasive plant by invasive plant in order to restore the integrity of this wild community; to heal and nurture relationships formed over eons, interconnections that sustain the health of the whole planet; to counter the damage caused by species that have a place and relationships on other continents, but which can be dangerous here, disrupting the community and harming the whole landscape. For me, nurturing biodiversity is a spiritual calling. This work is a step toward honoring and healing all beings—humans, bears, sagebrush, yellow bells and bumblebees, elk, deerflies, song sparrows, and the Earth we hold dear; our home in the immensity of space.

Cow Elk and Calf in Yosemite

What makes a species invasive? It’s not about a prejudice against immigrants. Tens of thousands of non-native species call the United States home without causing harm. But not every species belongs everywhere. Invasives are those relative few who don’t play well with others, the species who behave badly, a detriment to us all. Researchers estimate that the United States hosts some six thousand invasive species—plants, animals, insects, microbes—and these misbehaving lives cause a cool $137 billion in damages each year. That’s enough money to buy Twitter, Yahoo, and Toyota, plus BMW, Burberry, Prada, and Louis Vuitton, and add British Airways and Addidas (as of 2018 valuations). Invasive plants alone wreak havoc on an area about the size of California, which is a lot of territory to weed.

Sometimes species that become invasive start out relatively innocuously and continue that way for generations before something in the environment or their genes triggers explosive growth in their population. That’s what scientists speculate happened with salt cedar or tamarisk, a small tree with tiny succulent leaves and pink clouds of flowers in spring. Salt cedar was first imported into this country in the late 1800s for erosion control and as an ornamental. The small tree fulfilled those functions without much fuss until the era of big dams changed the flow of western rivers and streams. Efforts to control scouring floods created the perfect storm for these Eurasian plants to sprout in dense thickets, crowding out native cottonwoods and willows, poisoning fertile river-bank soil with their salty leaves, and drinking so much water that whole springs and streams vanished, their beds dry.

Other invasive species are bad news right from the start: for example, Russian knapweed, which exudes poisons to clear the ground and take over; zebra mussels, which simply crowd out all other species, or Asian longhorned beetles, which kill their arboreal hosts outright. We tend to go after invasive species with a military-style, kill-everything strategy, broadcasting pesticides and leaving scorched earth—bare soil—in our wake. Perhaps that’s the best approach for huge infestations, but sometimes we only succeed in clearing space for the next opportunistic invader.

I prefer a patient, chemical-free, long-term strategy of digging up or removing these disruptors plant by plant, then seeding in natives to replace them. For me, the work is personal. Invasive weeds endanger the places that nourish my heart and spirit. As I squat and sweat and dig, I am reminded why the effort matters; listen with me to the hermit thrush whose fluting song echoes through the clearing in the forest just off Upper Terrace Road, where I am weeding on a June morning. Do you hear the long clear opening note, followed by the softer rising and then down-slurred notes? Ohhhh, lovely, lovely, ah, happily, happily. Then, Eeh, sweetly, sweetly.

What do invasive weeds have to do with our singing thrush? Remember that houndstongue crowds out the bunchgrasses and wildflowers whose interrelationships weave the fabric of these landscapes. One of those interrelationships is with native insect species, and I’m not just talking about the mosquitoes whining around us. Soft-bodied insect larvae are the primary food most birds, including our hermit thrush, feed their young. Entomologist Douglas Tallamy, author of the important book on gardening with nature, Bringing Nature Home, writes that a nesting pair of chickadees needs six to nine thousand insect larvae to raise a single brood. Imagine how many insects a much-larger pair of hermit thrushes would need to catch. Yet, invasive plants support very few insects. When these plants take over, they create food deserts for nesting birds. No insects means no songbirds, and thus no fluting thrush singing to brighten a chilly and gray day.

An infestation of invasive plants crowding out the sweet-smelling spreading phlox and feathery yarrow, the fleabane and sunny yellow arrowleaf balsamroot blooming in the clearing where the hermit thrush sings means less food for the native bees, moths, and butterflies, plus hummingbirds and other pollinators. It means changes to the soil chemistry and thus to the micro-fauna and flora who help keep that underground world fertile and store carbon where it won’t accelerate global climate change.

And of course, plant communities altered by invasive weeds affect food and habitat for the “large charismatic wildlife” who attract millions of visitors to Yellowstone, like the cow elk who strolled her gangly, long-legged calf right through my campsite not three yards from where I sat on my truck tailgate, eating dinner. From elk and grizzly bears to fluttering azure butterflies, invasive species—those playground bullies of the world—disrupt Earth’s balanced, healthy natural communities, impoverishing us all.

Perhaps it sounds a bit crazy to spend vacations digging weeds in a national park, but it’s natural to me. I come from a family culture rooted in science—particularly, in the study of nature—and animated by a mission to leave the world in better shape than we found it. As a kid, I participated in civil-rights marches and volunteered at inner-city settlement houses with my family. Every summer, we piled into our family vehicle, a tradesman’s van converted into homemade camper, for months-long treks to the wild reaches of the continent. It was during one of those marathon camping and nature-study expeditions that I first recognized my terraphilia, our species’ in-born connection to and affection for Earth and her living inhabitants.

I was nine, and my father was driving, gas pedal to the floor, urging the engine of our van to its top speed on the brand-new pavement of Interstate 80 somewhere west of Laramie, Wyoming. My mother, as chief navigator, sat in the seat next to him, my brother scanned the passing landscape for birds new to his life list. I, ever the reader, kept my face buried in a book. The engine knocked hard, my father shifted down, and I looked up. Elk Mountain, splotched with spring snow, rose out of the expanse of shrub desert like a massive ship, its prow pushing aside wave after wave of sagebrush, silver-green and spangled with spring moisture. Lupine exploded in purple spikes between the shrubs, and the air pouring in the open windows bore a fragrance I still find intoxicating: turpentine mixed with piney resin, leavened by the sweetness of honey and orange blossoms.

Big Sagebrush with Jardine Valley in the distance

Sagebrush, I said to myself. I’m home. My heart swelled with feelings a child could not explain.

After my second year in college, I moved to Wyoming’s sagebrush country, found work in Yellowstone, and returned to classes and textbooks as little as possible thereafter. I got my first job as a field ecologist in a place where Big Sagebrush perfumes the air. I wrote my first scientific publications, married for the first time, divorced shortly after, married more wisely the second time. I wrote my first weekly newspaper column there. It was in Wyoming’s sagebrush country that I decided to trade my career in science for writing the stories I read in the data. The course of my life was set during those years in the sparse and lonely landscapes of the state I call home—the place where sagebrush is the landscape, its twisting trunks and tiny, three-tipped leaves forming silvery-green, horizon-spanning “seas” perfumed by the shrub’s distinctive scent.

Scientists named the plant I love Artemisia tridentata, the first part of that binomial honors the Greek goddess Artemis, an apt name for the shrub that is definitely the goddess of the high desert; the second part describes those three-toothed leaves. Most folks just call the shrub big sage (although it is not related to the sage familiar from turkey stuffing). Whatever the moniker, this gray-green shrub with the small, felty leaves is the most common shrub in the inter-mountain West. Its silvery, evergreen foliage tints miles and miles of open landscape between the Rocky Mountains and the Sierra Nevada and Cascade ranges, from Canada south to northern Arizona. When rain hits these expanses, Big Sagebrush suffuses the air with its signature fragrance. One whiff and I am home.

At nine, I didn’t know why I loved sagebrush, just that it identified the place where I belonged. After I studied the plant as a scientist, I came to realize that big sage is so tightly woven into the landscapes where it grows that each defines the other. Loving the West means loving sagebrush too. The shrub is supremely adapted to wind-blown, arid, cold-winter places. The conditions of each site shape sagebrush’s form, ranging from knee-high and wind-pruned on exposed ridges to giants nine feet tall in protected sites with deep soil. The three-tipped leaves are small and covered with an insulating felt of hairs to minimize water loss, as well as to protect the plant’s cells from sun- and frost-burn. Sagebrush retains those tiny leaves year-round to capture sunlight and power sugar production even on warm days in winter. The shrub is so attuned to its environment that the plant actively reorients the leaves throughout the day in response to the movements of sun and wind.

Sagebrush also communicates. The shrub’s abundance and evergreen foliage make it attractive food for legions of grazing creatures, from microscopic mites to half-ton ungulates. Sagebrush protects itself by broadcasting that signature fragrance, a complex blend of dozens of aromatic chemicals, as a warning. The turpentine-like smell announces to grazers that the plant’s tissues taste bad and are gut-cloggingly difficult to digest.

Mark Twain recognized the vital relationship between sagebrush and the landscapes of the West in Roughing It when he called the shrub “an imposing monarch of the forest in exquisite miniature.” The polka-dot canopy of sagebrush does in fact act like a forest overstory, offering shade and blunting the constant wind, buffering both searing daytime temperatures and frigid nights, and limiting evaporation. The leafy canopy also traps airborne dust and detritus rich in organic matter and mineral nutrients to enrich the soil. It captures rain, channeling scarce water into the ground along the shrub’s roots, which reach as deep as twelve feet. Big sage even collects its own mini-snowdrifts in winter to provide spring moisture. The shrub whose fragrance and form delineate home to me is also home to over 350 kinds of wildlife, from pronghorn antelope and sagebrush lizards to pygmy rabbits, flashy black and white hera buckmoths, and greater sage-grouse, whose drumming and dancing on ancestral leks—mating grounds—signal winter’s end.

More clearly than any national border or cultural identity can define, I have come to realize that my allegiance and sense of belonging are bounded by sagebrush. My primary loyalty is not to any political party or ideology, it is to the land itself, and to the community of lives whose interactions animate this vibrant planet. Since childhood, I have held plants dear. They are my tribe as much as my fellow humans—perhaps more on some days. I admire these rooted beings for their self-sufficiency, the way they use the simplest and most common materials—carbon dioxide, water and minerals, plus the sun’s energy—to make their own food: complex sugars that feed every other life on Earth, directly or indirectly.

Plants are Earth’s life-support system. They grow the interdependent communities that form our planet’s living infrastructure, providing food and shelter for all. These are not passive beings, as we so often think: plants actively sense and respond to the world around them. They communicate using an aromatic vocabulary of airborne chemicals. For oxygen-dependent beings, plants are “breathing-buddies,” as the poet Clifford Burke writes. They exhale as waste the oxygen we inhale, and then inhale the carbon dioxide that we and our industrial processes off-gas (to excess, causing global climate change). Our relationship with these green beings is crucial to our continuing existence, evident in every single breath. For me, their presence is also a balm I need to survive in an increasingly wounded world.

Hood’s Phlox blooming in Yosemite

I realized this is my place and work after two seasons spent volunteering as one of a dozen or so “weed warriors” who dig invasive plants in Yellowstone. There is a kind of grace that comes with kneeling on the soil, grubbing weeds in service to the community of the land. The work nourishes my sense of wonder. I arrive in Yellowstone in June when the soil is still moist from melting snow, and it is baby season: I watch elk calves so new they still wobble on their legs. I recognize the herd-mama’s “Wah-ooo-ee!” call, which means “Get over here now!” and the calves’ “Wah! Wah!” cry, which could mean, “I’m hungry!” or, “Where the heck are you?”

I’ve seen pronghorn fawns still wet, fur matted with after-birth; glossy black bear cubs; and baby wrens and bluebirds. The babies are everywhere, from baby Richardson’s ground squirrels, the lunch-meat of every larger predator, to baby snakes. It’s also make-plant-baby season, when the silvery sagebrush country is spangled with bright pink bitterroot flowers, yellow lomatium, scarlet Indian paintbrush, blue Lewis flax, purple Rocky Mountain iris blossoms, buzzing with pollinators of every sort helping the flowers seed the next generations.

Over the summer, I watch those babies—plants and animals—grow up and learn how to be independent, trying out their place in the interrelationships that make up the wild community of Yellowstone. Their antics keep me entertained when the squatting and digging makes my calf muscles scream and my arms burn. The work is hard, but—oh—seeing the native grasses and wildflowers sprout where I have cleared invasive weeds lifts my spirits. Such small miracles remind me that I, too, belong here; and that humans have a positive role to play in this world. Yes, we can destroy thoughtlessly. But we can also restore and, in doing that, find some measure of healing and goodness for ourselves and our species.

My days in the park are simple and retreat-like (albeit physically grueling). I wake with the light at 5:30 a.m. or so. I greet the day in my sleeping bag as robins, western tanagers, chipping sparrows, and other birds weave the dawn chorus. Once up and dressed, I set my backpacking stove on my truck tailgate to boil water for instant oatmeal. As I scarf my hot meal, I think up my daily haiku, a daily practice of celebrating the moment and the blessing of this existence; it’s also my gift to social media, a reminder to engage in what Thoreau called “the actual world” beyond the screens of our devices.

After breakfast, I drive up uphill to the Mammoth Store, fill my to-go cup with cocoa from the machine, and then head for my work site. After checking to make sure I have weed bags, first-aid kit, bear spray, water, and extra layers in case of rain or snow, I shoulder my day pack and set off.

Then I dig houndstongue and other invasives until I wear out, usually around noon. While I work, I scan my surroundings for wildflowers and wildlife, like the sow grizzly bear with twin cubs I saw one day from a distance. After I hike back to the truck, I dispose of my day’s haul of weed-filled trash bags, take off my gloves, clean my plant knife, and head back to camp for lunch. The rest of the day is my time. Some days I drive out of the park and hang out in a coffeehouse in town to charge my laptop and cell phone, and use the internet. Or go to the grocery store, take a shower, or do laundry. Some days I want more solitude, so I ramble in search of new wildflowers. Or perch on a rock in the sun and read a book or write a letter.

After eating a simple dinner, I crawl into my truck-topper with its super-comfy, four-inch-thick Thermarest mattress, sleeping bag, and pillows. Cozy, I read or write in my journal until sunset. After which I say my gratitudes for the day, brush my teeth, and sleep soundly, snug until the light wakes me to hear the dawn chorus reweaved. One morning’s chorus began with the distant howling of wolves, a ululant and wild grace.

Those gifts of the wild make the hard, physical labor of weeding worthwhile: the squatting, digging, and yanking on stubborn weed plants; the bumping back down the trail at the end of each session, sweaty and lugging overstuffed trash bags, my back and calves aching. I refer to my weeding-time in Yellowstone as a “spa vacation,” only half-joking. In just one ten-day stint, I hiked 47.5 miles, pried out approximately 3,050 plants, and hauled off 25 trash bags weighing a total of 290 pounds.

Does hand-weeding work? My experience over many restoration projects indicates, yes, it does, especially for spot infestations and in places where using pesticides is risky. Hand-weeding worked for the elk fawning area in and around the north end of the Mammoth Campground in Yellowstone, where a herd of several dozen cow elk stash their newborn calves for the day, hiding the gangly youngsters in tall clumps of basin wild-rye or chokecherry thickets while the moms head off to graze tender vegetation elsewhere. It worked for the block of urban creek I spent two decades restoring to health, with northern dippers warbling in the street culverts in winter and monarch butterflies nectaring at pink milkweed blossoms in summer. The first year I weeded the calving grounds of Mammoth Campground, I dug so much houndstongue I thought I would never make a dent. But by the next spring, between my effort and that of my fellow weed warriors, the remaining houndstongue existed only as scattered clusters. We may never eradicate it completely, but we’ve kept it from taking over.

Yellowstone is a huge place, and the Park Service’s limited budget pays for just two crews to control weeds over an area larger than the Los Angeles metro area, with far fewer roads. When the magnitude of the task overwhelms me, I remind myself that with enough time, hands, and persistence, we can restore communities, plant by plant. I’ve seen it happen.

Weeding is a wonderful way to reconnect humans with nature. When I walk through the campground in my volunteer uniform lugging trash bags bulging with plant carcasses, people are curious and ask what I am doing. I point out houndstongue and other invasives, and I explain why I dig weeds. Most of us never think about plants, other than perhaps when we bite into a juicy peach or admire a spreading tree. We don’t consider how these photosynthesizing beings shape our planet and our lives. A glimpse into their interrelationships opens a door to appreciating the diversity of lives on Earth. Hearing about one specific way humans can make a positive difference in the world is inspiring. People often thank me . . . and ask how they can volunteer, too.

Doing good is also good for me. Even if my inner economist reckons the dollar cost of my weeding as high—as a freelance writer, I don’t get a salary and vacation time; I am only paid when I sell my work. But weeding pays in so many other ways. The truth is, I cannot afford to not do this work. Weeding to nurture biodiversity is my gift to capital-L Life, the greater community of nature that weaves our earthly home and allows me—and all of us—to live. The light in my soul as I lug another heavy bag of weeds down the trail is Life’s gift to me.

We all benefit from giving back, from making positive statements in a world that feels far too negative. Weeding to heal the landscape that holds my heart restores my faith in the resilience of life. At the end of the day, my muscles may be sore, but my spirit sings with the hermit thrush.

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  • Susan J. Tweit

    Susan J. Tweit is a plant ecologist who has studied grizzly bear habitat, wildfire behavior, and sagebrush communities. She writes widely for magazines and newspapers, is the author of twelve books, and has initiated several community nature restoration projects. She lives in northwest Wyoming near Yellowstone National Park.

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