Invasive Plant Species in New England

Kill Them All? Learn to Live With Them? There are no easy answers when “invasive” plants move into our forests, meadows, and backyards. But first we need to know what questions to ask.

On a sunny October morning, at the edge of a gravel road just off U.S. Route 7 in Charlotte, Vermont, I watched the Green Reaper approach. He rode in the passenger seat of a maroon Ford F-250 pickup; as he passed, he flashed a broad smile and motioned for me to follow. The bed of the truck, I knew, carried the tools of his trade: Glyphosate. Imazapyr. Triclopyr. And, so that he might kill as quickly and effectively as possible, back-mounted sprayers with coiled loops of tubing through which his chemicals would run. I followed as the truck rolled slowly down the road. It stopped briefly by a small pond, so that the Reaper and his driver could admire a flock of ducks basking in the atypically warm weather. The truck started moving again, then veered left into a private driveway. It pulled onto the grass and parked, and the Green Reaper emerged, smiling again, hand extended, bushy eyebrows raised in friendly greeting. In other words, ready to kill.

It wasn’t the first time I’d met the man, whose real name is Markus Bradley and who, I should state in the interest of full disclosure, was raised in the same rural Vermont town as I. Along with Markus’s twin brother, we’d been childhood friends, though we’d fallen out of regular contact as we’d entered adulthood. But I’d kept close enough tabs to know that Markus had married, had three children, and settled in Vershire, Vermont, where he was a partner in a forestry consulting business called Redstart and maintained a keen interest in the sport of ice hockey. So it was Markus I’d called when it was time to update our forest management plan under the state’s current-use act. And it was Markus who’d spent three hours walking our 30-acre woodlot with me, moving quietly and quickly through the understory, showing me where a bear had marked a maple with its ample claws and admiring the handful of red oak growing on our land. “Don’t usually see these so far north,” Markus had said. “It’s real nice to see.” But there was something else that Markus had pointed out that day, something that in only a few short years has utterly redefined the nature of both his career in forest management and his relationship to the New England landscape: invasive plant species. Indeed, we hadn’t gone more than 100 feet into the woods behind my home before Markus discovered the first specimen, a bush (a.k.a. shrub) honeysuckle: in my case, one belonging to the Lonicera genus, not the low Diervilla honeysuckle that’s native to New England. We sidled up to the verdant plant, with its numerous, spindly stalks, and Markus gathered a cluster of small, oval leaves in his hand. He looked at me with intent. “Once you get tuned into what this plant looks like,” he said, as he gave the handful of foliage a shake for emphasis, “you’ll be horrified, because it’s everywhere. And once you know, your innocence is over.” It is said that ignorance is bliss, which may be true, but if so, that doesn’t account for the fact that once an ignorance is exposed, it often seems as if the only relief is to expose it further. That’s what Markus promised he could do for me, although he warned me that I should be careful of how much I let myself know. “I had one woman tell me I ruined her walks in the woods,” he told me, and he looked as though he actually felt bad about it. I wasn’t keen to suffer the same fate, but it was too late, really: A few hours with Markus in a piece of forest I know better than any other place on earth, and already I’d come to see it in an entirely different light. No longer did it feel like an escape from the pressures of work and family, like a place to ramble carefree and untroubled, soothed by immersion in a world where things happened because they were supposed to happen, unfettered and unadulterated by the hand of humankind. Now I couldn’t walk through my woodlot without seeing the encroachment of invasive species everywhere; what before I’d assumed to be noble and beneficial players in nature’s self-regulated game, I suddenly understood to be something undesirable and even rapacious. “Unless you do something, in a few decades you’re not going to even recognize your woods,” Markus told me. “This is a whole new deal.” Then he dropped his voice, as if confiding something: “To tell you the truth, there’s a bunch of plants coming that scare the s– out of me.” My innocence was over. I had to know more. Given the recent defiling of both Markus’s innocence and mine, one could be forgiven for thinking that invasive plant species are a contemporary issue, a 21st-century blight on the landscape. And although there’s evidence that some species have become more established in certain regions over the past decade or so, the history of invasive (also known as “exotic” or “non-native”) plants in New England is as long and as storied as the history of the Europeans who settled here. That’s because the early settlers carried more than woolen knickers and musket balls when their ships anchored off the stony shores of New England: They also carried the seed and stock of their favorite edible, medicinal, and ornamental plant species. Indeed, there’s evidence that humans intervened in the distribution of vegetation even earlier: Some researchers believe that nomadic tribes of Native Americans traveled with their favorite plants. Truth is, this continent would likely not have been settled by Europeans were it not for introduced plant species. Of the world’s 20 most prominent food and industrial crops, North America has contributed few originals, corn and sunflowers among them. (Central and South America, of course, have contributed more.) The limited number of other major crops indigenous to the north include blueberries, cranberries, grapes, pecans, and possibly beans and squash (though many other smaller crops are also native). Not exactly the sort of fare upon which a nation is built, which is the very reason that one of the U.S. Navy’s earliest and most important tasks was the gathering of cultivatable plant species from foreign countries. Of course, no one’s arguing for the eradication of the edible plant species that feed America. That would be a very bad idea. There’s clearly a distinction to be drawn between plants that have been introduced as beneficial cultivars and those that have been introduced for aesthetic purposes (many of the species that Markus Bradley spends his days executing were introduced for strictly ornamental purposes) and have since proliferated in the wild, where they’re rapidly altering the region’s forested landscape for what is likely to be generations to come. Back in Charlotte, Vermont, I followed Markus and Redstart employee Courtney Haynes on a circuitous loop around the perimeter of the client’s property. The previous autumn, the Reaper and Courtney, along with a pack of students from the nearby University of Vermont, had invested nearly 500 hours spraying, cutting, and hand-pulling invasives throughout the 30-acre parcel. “Oh, we cut some monsters in here,” Markus told me, pointing to a buckthorn stump that measured a good five inches across. Everywhere I looked, the ground was littered with dead and decaying plant tissue; withered specimens hung from branches, where they’d been marooned so that their roots would never again find succor. There was honeysuckle, mostly, but also buckthorn and bittersweet and … well, pretty much every introduced species common to the region. “It’s like someone scattered the invasive-species seed mix,” Markus said. “It’s a s– show in here.” One of the things I was beginning to appreciate about Markus was his plainspoken manner, reflected in his speech, as well as his physical bearing and general countenance. If there were a single word to describe the way he presented himself and even how he moved through the woods, I thought it might be “unfussy.” After a few minutes of strolling through the treated area, we arrived at the property’s edge and, concurrently, one of the greatest conundrums facing Markus Bradley and anyone engaged in the process of invasive-species control: Mere inches from where we stood, across the invisible line demarcating one piece of property from another, the forest understory was a dense mass of greenery, punctuated by slender masts of vine and branch, overwhelmingly of the very same species that lay in purposeful ruin behind us. It would be an exaggeration to say that it was impenetrable; it would not be an exaggeration to say that it didn’t look anything like the Vermont forest landscape in which I’d been raised. It didn’t look like the sort of place where I’d want to go for a walk. Plants, of course, don’t respect property boundaries; they don’t discriminate between one piece of land and another. Across the line at our feet lay thousands of acres, apportioned into private ownership according to innumerable deals made over hundreds of years. In Markus’s own words, the efforts to eradicate the invasive species on the piece of land on which we now stood amounted to little more than a “doughnut hole”; beyond the hole, as evidenced by the thriving crop of honeysuckle, buckthorn, and barberry before us, the invading plants grew and flowered. They dropped seeds and released them to the wind. Birds fed on their berries and then flew away, to distribute the seeds as the urge struck. “Does it ever feel futile,” I asked Markus and Courtney, “to know that no matter how many hours you work, how many plants you rip from the ground, or douse with glyphosate, or otherwise destroy, no matter how many doughnut holes you make, these species are all but certain to continue to spread and even prosper?” Markus sighed, and gave the closest thing to a non-answer I believe he’s capable of: “Every time I come up here, I have more incentive to be serious.” Then he turned his back to the living vegetation at the periphery, and started walking. Markus had taken me to the “doughnut hole” for what I assumed to be two reasons: to show me what a treated piece of property looks like, and to demonstrate what might happen to our property if we let it go. It’s no exaggeration to suggest that he views his work as something of a mission; when we parted ways on that bright October day, my ears rang with his parting warning: “Almost 100 percent of the properties we look at have invasives. From what you’ve seen today, I hope that’s troubling.” And it was. But I was also troubled by something else, though I couldn’t quite put my finger on it. Still, I knew it had little to do with Markus, beyond his being the person responsible for exposing my ignorance. But I couldn’t blame him for that, and besides, I was glad for the information. No, what bothered me was something less tangible but no less affecting, something that was rooted in my emotional response to the issue. I suppose it’s easiest to explain it like this: The day before Markus’s visit to our property, I had embarked on a short walk in our woods. I do this frequently, often visiting the tumbledown stone foundation of an old sugarhouse, where I like to sit atop a particularly commodious slab of basalt and consider the lives of those who’d stoked the ever-hungry arch, now collapsed and half-buried by a century’s worth of autumnal leaf-shedding. On this walk, I’d passed directly by a handful of the very plants to which Markus had alerted me; heck, I’d probably brushed up against one or two. The day before, I hadn’t known that there was anything wrong with these plants; I was blissful in my ignorance, viewing them only as part of our forest’s ecology, an ecosystem that never fails to offer me comfort and inspiration. The day after was very, very different. I’d tuned into what the offending plants looked like, and as Markus had promised, I was horrified. Suddenly, it seemed as though ruin lay around every fir and spruce, as though every stately sugar maple were merely a distraction from the despots of our woodlot. Even the red oaks, which Markus had so admired, seemed somehow diminished by the knowledge that an infestation of invasive plant matter flourished in their shadows. If I did nothing, soon I wouldn’t recognize the wooded landscape in which my children now romp and play. And when they grew to adulthood, would they even be able to remember the forest of their childhood? Or would it be rendered a nearly impenetrable mass, like the one I’d seen that morning in Charlotte, across the line dividing the doughnut hole from its perimeter? This is all sounding a bit dramatic, I know. Still, it’s nonetheless the truth, and for a period of about three weeks, I fretted almost continuously over the pending ruination of our forest, to the point of opening a rift between my wife, Penny, and myself, with me advocating for chemical control, per Markus’s recommendation, and Penny, who’s spent her entire adult life managing organic farming operations, insisting that no chemicals would be sprayed on our land. But in my more lucid moments, I had to ask myself what, really, had changed? Not the plants; two days prior, they’d been the exact same specimens I’d fondly regarded as constituent pieces of my beloved forest. They certainly weren’t inherently ugly. And bush honeysuckle, the most prolific of the invasives on our property, even smells nice, like a spoonful of its namesake sweetener left in the sun. Indeed, the only thing that had changed was that I now had a name for them; the only thing that had changed was my perception of these plants. I realized that it wasn’t the Green Reaper who had ruined my walks in the woods; I had done it to myself. Penny could see my struggle (hell, anybody could). So she did the sanest thing she knew how to do: She pushed me out of the house. “At least do some research,” she implored, all but slamming the door behind me. “Maybe there’s another perspective out there.” Lo and behold, she was right. When Dave Jacke has a strong opinion on something, which is often, he speaks loudly–yells, really–then leans forward from the waist and punctuates his point with this exclamation: “WHAT THE HELL?” As in: “People say ‘native’ and ‘non-native’ as if they were scientifically valid terms. But no quote-unquote ‘native map’ has no date on it.” He leaned forward: “WHAT THE HELL?” And: “If we’re going to start calling these plants ‘invaders,’ and not take ownership for our own human behavior …” He leaned forward: “WHAT THE HELL?” Finally: “Black locust is illegal to plant here, yet we’re importing pressure-treated lumber from the Southeast and polluting our soils.” He leaned forward: “WHAT THE HELL?” I’d found Jacke through my friend Ben Falk, who runs a permaculture design school called Whole Systems Design in Vermont’s Mad River Valley. Permaculture has a complex and somewhat malleable definition, but at its essence is based on the interconnectedness of natural and human ecosystems; it seeks to foster a philosophy of working in accordance with nature, rather than attempting to control nature for humancentric purposes. Falk encouraged me to speak with Jacke in part because of his knowledge of the region’s plant species, in part because he’s the co-author of two books on the subject of permaculture, and in part, I suspect, because he knew that Jacke’s stance on invasive species would be well articulated, well researched, and passionate in the extreme. All of which was true. Within minutes of meeting Jacke at the door of his second-floor apartment in Greenfield, Massachusetts, he was challenging the very foundation on which the basis of our battle against invasive species is waged: that there is any scientific basis for our determination regarding what is native to the region. To make his point, Jacke pulled up the National Oceanic and Atmospheric Administration’s pollen viewer, an interactive online map that lets the user select a species, then a time frame. Click on “enter,” and you can watch species drift across hundreds and thousands of years, carried by unidentified vectors. “Check this out,” he said, as he typed in Castanea dentata, the Latin name for the American chestnut, a tree species that has largely been lost from New England owing to blight. It’s a loss that has been much bemoaned, and restoration efforts are ongoing. Castanea dentata, it should be said, is considered native to the Northeast. Except that it’s not, really. At least not according to NOAA, which has the species first appearing in New England about 3,000 years ago, on a march northward from its origins in the Deep South via the mid-Atlantic region. Now, 3,000 years is a very long time, and Jacke’s not claiming any differently. Rather, he’s making what seems to me a quite valid point: Without an agreed-upon definition of “native,” how are we to determine which species meet that definition and which don’t? Furthermore, our forest ecology isn’t static, and many species that we now consider “native” were, in fact, once invasive. Except in Jacke’s view, the word “invasive” isn’t right, either, because it ascribes human intent to species that are simply trying to do what plants do best: survive and propagate. “Where do human values come into the equation?” he asked. “The word ‘invasive’ has values implied. Besides, if we’re going to start calling all these plants ‘invaders’ and not take ownership for our own behavior …” He leaned forward, and I knew what was coming next. Dave Jacke is no lone wolf in his opposition to the current framing of the non-native-species issue as one demanding urgent battle to thwart an aggressive enemy. Indeed, the more I poked around, the more people I found who hold the view that our ecosystems are in a constant state of flux. Part and parcel of this view seems to be an understanding of humanity’s role in the spread of non-native species, both in regard to the actual act of disseminating the plants via horticulture and in humans’ impact on the land, which tends to create soil disturbance and therefore opportunities for non-native flora to prosper. To better understand this view, I called Mark Davis, professor of biology at Macalester College in Saint Paul, Minnesota, and author of the book Invasion Biology, which, despite its title, is decidedly skeptical of the field as a whole. Davis is nationally known for his rebuke of the dominant us-versus-them view of invasive species. It’s a position that has at times been uncomfortable to maintain; Davis has actually received hate mail, deploring him for his contrarian position. Like Jacke, Davis believes that our definition of “native” is flawed, and is therefore leading us down the wrong path in response to non-native species. “On some level, it’s about baselines, about what we’re used to,” he said. “Look, the New Hampshire state flower is non-native. And so is Vermont’s state insect.” (After our conversation, I fact-checked this assertion, and he’s right. The New Hampshire state flower, the purple lilac, was imported from England during the first half of the 1700s. And Vermont’s state insect, the European honeybee, was introduced to North America in the 1600s.) Furthermore, Davis contends, the typical response to non-native species–spraying them with herbicides–only compounds the problem: “We’re doing more harm by spraying all these chemicals, which disrupt healthy soil biology and probably just make it more susceptible to opportunistic plant species.” Interestingly, this was something that Markus had noticed: In some of the areas he’d sprayed to eradicate one non-native species, another had popped up. Both Davis and Jacke are very clear that they’re not calling for an entirely hands-off approach to invasive plant species–only that our efforts should be carefully considered and dependent on regional and even site-specific goals. “There are introduced species that are doing real harm,” Davis noted. “We shouldn’t get sidetracked by species that [represent] really just change and not harm.” He sighed. “Look, trying to re-create the forests of the past is simply not possible.” For his part, Jacke believes we need to accept that some areas are going to become “overrun” with non-native species: “I think it’s a good idea in places to let them go nuts, so we can see how the ecosystem adapts. So we can learn.” He opened his eyes wide. “I mean, let’s be honest: We know so little about this stuff. The basic assumption we have to have is that we know nothing.” “Okay, fine,” I said. “I get it. I know nothing.” Given all that, what did he think I should do about all the honeysuckle taking root in my woods? Jacke didn’t hesitate for a second: “Oh, man, I don’t like that stuff. If I had it on my land, I’d be pulling it out.” As so often happens, I’d gone seeking clarity and ended up more confused than I’d been in the first place. Are invasive plant species a threat to the region, or are they not? Should I even be calling them “invasive”? And what constitutes “native,” anyway? I’d come to realize that there are no easy answers to these questions, and even Markus, as avid a hunter of these species as likely exists, acknowledged as much. “This thing is still in its infancy,” he told me, when I called him one winter’s evening to confess my quandary. “We don’t know how effective or ineffective we’re going to be over the long haul. If things are in check, these plants shouldn’t be impacting the ecosystem in a harmful way. But we just don’t understand all the relationships.” Goodness … had the Green Reaper knelt at the altar of permaculture? I was struck by the similarity between his words and Jacke’s. And he wasn’t finished: “For instance, how is non-native honeysuckle impacting your forest? I’m not sure I know yet.” To Markus, terms like “non-native” and “invasive” are really just placeholders for a basket of characteristics and, like most language, are subject to nuance and bias. Take the common dandelion (Taraxacum officinale), so ubiquitous that few question its place in the New England landscape. Yet it was introduced by the Puritans, reportedly for its medicinal properties. (In Europe, dandelion is commonly used as a diuretic and a diabetes treatment, among other applications.) So, yes, the dandelion is a “non-native” or “invasive” species. But in Markus’s view, the plant is benign and perhaps even beneficial and therefore doesn’t warrant action. Still, he noted, not everyone agrees. For instance, farmers trying to put up dry hay hate dandelions, because they hold significant moisture. “In my narrow view, the dandelion isn’t invasive,” Markus noted. “But a lot of farmers would disagree.” Markus’s work on non-native species has even begun to inform other aspects of his forestry practice. He’s noticed clear parallels between timber harvests, which by their very nature create significant soil and canopy disturbance, and the influx of non-native species. He’s even started to turn down certain jobs. “It’s not respectful to the ecosystem just to make a few dollars,” he told me. All of this made good sense, and even if it didn’t answer my questions directly, it began to add up to a context against which I could answer them for myself. In short, only I could decide whether the plants growing in our woodlot constituted a threat; only I could decide what to call them and how to perceive them. Thus emboldened, I set out on an early spring morning to walk our woodlot. I wore heavy work gloves, so that I could find the grip necessary to uproot the more stubborn bush honeysuckles I stumbled across. But despite my intent, I no longer had the frantic sense that I had to either fight relentlessly or concede. I had come to recognize between these two extremes a wide swath of middle ground, and it is there that the sacredness of my relationship to the forest is restored. It’s true that I don’t wish to see our woodlot transformed, but I know now that what I want has little bearing on the multitudinous and largely unknowable laws governing the ecosystem, of which I am only a part. As I strode under the tree canopy, I remembered something that Jono Neiger had once said. Neiger, who used to managed invasive species with an ATV-mounted boom sprayer and gallons upon gallons of chemicals, is now a professor at The Conway School, a Massachusetts-based institute that offers a graduate program in sustainable landscape planning. “We’re not getting at the root cause, which is an incredibly disturbed landscape due to human habitation,” he’d told me. He’d paused for a second–not a dramatic pause, but the sort of pause that suggested he was trying to decide exactly what to say: “We believe that we’re separate, but we’re not. There’s no way we are.” Deep in the Vermont forest, with the morning’s slanting light still feeble and uncertain, I stopped. I heard birdcalls, high and trilling. I smelled the mustiness of the day’s dewy beginning, mingled with the acridness of my perspiration. “We believe that we’re separate,” Neiger had said. Not anymore, I thought. Not anymore.

Identify Invasive Plants