To My Fellow Foragers: Non-Native Plants Also Deserve Our Respect

Immigrants are real participants in their adopted homes

St. Johnswort (Hypericum perforatum), as observed in Oregon's Willamette Valley [Photo by author]

I've been wildcrafting medicinal herbs and foraging wild and feral foods for a little over twenty years in a variety of settings from wild to agricultural to urban, and in a number of regions including the moist, verdant Pacific Northwest, the oak-dotted, golden hills of California, and the arid, sagey Great Basin. I've processed my harvests by tincturing, sundrying, canning, wine-making and other ways. These herbs are my primary medicine cabinet, and this food helps sustain me year-round. I'm happy to see that a growing number of people are becoming engaged in these satisfying activities.

Foremost among the concerns of any forager or wildcrafter is plant ID. We need to know what we're picking! Besides avoiding plants that are inedible or poisonous, we can tell (or can find out) when to harvest and how to process.

Next most important is the ethics of harvest, which is generally understood as how much to take so as not to harm the plant. People use rules like "no more than one third" though this is a case-by-case and season-by-season issue. That’s what it’s about when you see "sustainably wildcrafted" on tincture labels.

A third factor is seeking permission. This can mean inquiring with a landowner, as in "Hey can I pick those apples?" or "Want me to dig up your Dandelions for you?" On public land, there are rules about what and how much you're allowed to take. Many people, especially herbalists, also suggest asking the plant permission, and that can take many forms, from ceremonial to intuitive.

Additionally, on the subject of permission, who are the other-than-human creatures who partake of these plants? Are we poaching from their share? How can we ask them permission? What can we offer? To this last question, the wildtenders say, "plant back!" which is still a new concept for many foragers though it should be central to the endeavor, but that’s a subject for another day (or see my book, The Failures of Farming & the Necessity of Wildtending).

There's a lot of details to all this of course, but the basic guidelines are: "What is it?" "How much can I take?" (with “How do I give back?”) and "Who should I ask?"

Over the last few years an increasingly prominent aspect of plant ID has been whether the plant is native or not, and this is often mentioned right at the outset, just after the name. If the plant is not native, many foragers, herbalists or wildcrafters dismiss the above guidelines. The rationale is that since the plant "doesn't belong," it's not important to have any concerns about it.

This attitude is problematic for a number of reasons and it's time we move past it.

Many of the ideas that are circulating about non-native plants lack the scientific foundation that people seem to believe they have, and—what's more significant in my mind—are more the product of cultural biases. Put another way, certain popular narratives have left science behind but are widely disseminated anyway because they “sound right” according to a value system.

Two of the most common narratives about non-native plants are that a) they cause harm to native plants by "out-competing" them and b) native fauna depend on native plants and don't make use of non-native ones. But before we get to these, we must acknowledge two facts.

Fact #1: Unless we are told, we have no idea if an unknown plant is native or not.

This is because there is no observational method we can apply that differentiates native species from non-natives because there are no such inherent differences. A person familiar with the basics of botany, if dropped into a completely unfamiliar locale, could identify common plant families (think Asteraceae, Apiaceae and Fabaceae), but wouldn’t be able to spot the foreigners. Both native and non-native plants might be "weedy" in their growth habit, or impede the growth of their neighbors, or form monotypic stands—to name a few attributes often associated with non-natives. Likewise, both native and non-native plants might mature gradually, or form mutualistic relationships with their neighbors, or have a scattered distribution—qualities sometimes associated exclusively with natives.

So, in any given area, we are dependent on learned knowledge—from people or the literature—on a plant's place of origin. Why is this important? To keep us humble, frankly. In the case of native vs. non-native, we should always keep in mind that our conceptual binary overlay does not represent an intrinsic quality.

Fact #2: Regardless of where the plant is from, where it's growing when we find it is where it is at home at that moment, and that tells us something.

The presence of a plant in a spot reflects the fact that it is suited to the local ecological conditions, which include factors like climate, soil make-up, exposure to sun, level of moisture, mycology, etc., plus the influences of local fauna. In that sense, plants "belong" where we find them, and furthermore their presence—regardless of origin—is giving us all sorts of information about the location.

With regards to harvest, such information can be helpful. Nettles, for example—of which there are both native and non-native subspecies of Urtica dioica that are quite tricky to tell apart—can thrive in areas that are polluted with heavy metals or other toxins. The high mineral content that makes the plant so useful results from its ability to uptake substances from the soil, but that can include harmful substances. This is why herbalist Michael Moore warned against harvesting Nettles from ditches in farm country in Oregon's Willamette Valley.

With these two facts in mind—that a plant's place of origin can only be learned from received knowledge and cannot be ascertained by observation, and that plants grow in areas where they are "at home," which informs us about the area—we can move on to the two common narratives.

Narrative #1: Non-native plants “out-compete” natives

Scientifically, how many non-native plants are considered problematic? In the field of invasion biology, the generally accepted rule is that 1 in 10 imported species of flora and fauna end up in the wild, and that of these 1 in 10 are able to establish a self-sustaining population, and that of these, 1 in 10 plants become a “pest”—in “economic” terms. That’s 1 in 1000. Note that the “economic” is the word used. Ecological effects like competition with natives are another subject altogether and the lack of consensus in the field of invasion biology on such ecological effects is at odds with the fear-mongering language often common in media and discourse.

In North America, there is not a single documented instance of a native plant being driven to extinction due solely to competitive pressure from a non-native plant. The gravest threat to native plants by far is habitat destruction by humans (at 88%), and the biggest single driver is agriculture (at 86%). Think plowing under prairies, draining wetlands, taming rivers, deforestation and livestock grazing. Think also of the roads to connect it all, which are vectors for introducing non-native species, whether purposefully (virtually every single one of the domesticated crops and animals in the US for goodness sake) or accidentally (some of the "weeds").

In the wake of these highly impactful activities, the plants who thrive are those who are adapted to disturbance, and usually include both native and non-native species. Such species play important roles in ecological succession, like preventing erosion, renewing fertility, and providing habitat for the next phase of plants. Of the non-natives, some are plants who have spent centuries or even millennia adapting to the disturbances particular to agriculture, like tilled fields, ditches and fencelines. In our age of "better living through chemistry," we can add the adaptation of herbicide resistance.

So, should we jump to the conclusion that the non-native plants on the roadside, in the farm field, below the dam, in the clearcut, on the rangeland—or in the city—are "out-competing" the native plants? Or is it more accurate to admit that our disturbances wiped out native ecosystems and then we manufactured new ecological conditions (which include factors like climate, soil make-up, exposure to sun, level of moisture, mycology, etc., plus the extirpation of local fauna), conditions that are less hospitable to many of the original natives and more hospitable to some of the introductions?

When you consider just how darn much of the landscape in North America has been impacted by human disturbance, you can understand why non-native plants are so prevalent in many places: because we invited them in and made them at home. And now we disparage them? That’s called, “blaming the messenger.”

Narrative 2: Native fauna, like insects, require native flora, in part because that's who they co-evolved with.

That native insects require native plants has been a popular trope the last few years, and it has a certain common sense appeal in the context of the Western worldview (more on that below). As a lifelong lover of insects (who raised caterpillars as a child), this is a subject important to my heart. But common sense appeal is one thing and evidence is another, and this is a case where a popular narrative has left science behind. Probably most often cited on this topic is biologist Doug Tallamy, and this is not the place to take a deep dive into the merits and demerits of his work, but keep in mind that his first study entailed surveying residential yards in the Washington, DC, area. Not exactly expansive. (For detailed critiques of Tallamy’s work, see “Baseless generalizations in Doug Tallamy’s Nature’s Best Hope” and the list of other articles at the end, at the highly informative website, Conservation Sense & Nonsense.)

While there are examples of insects who specialize on just one species or small group of closely related species of plants, such as Yucca Moths, the majority can prosper on many species or genera (genuses) within a plant family or even across plant families. The term “specialist” as applied to insects can be misleading to a layperson since an insect that depends on one plant family can be designated as a “specialist,” but many families include hundreds or even thousands of species that include both native and non-native species.

Indeed, the dietary ranges of many insects have expanded due to the introduction of non-native plants. Some Swallowtail butterflies who are hosted by species in the Carrot Family appreciate the parsley, dill and fennel that we imported. Other Swallowtails who are hosted by the Citrus Family, have taken advantage of the many orchards we have planted. One study in California found that over 40% of all urban butterflies are now dependent on non-native plants. Also, ask any farmer or gardener whether the native insects feasting on her/his crops have successfully transitioned to introduced species!

As for the Yucca Moths, as various species of Yucca plants have been transplanted all over the country outside their native range, the moths have accompanied them.

The consumption of non-native plants by native fauna is not limited to insects. Again, ask a farmer or a gardener. Deer, rabbits and other herbivores have to be fenced out. Gophers, moles, voles and other burrowing creatures find our root crops delicious. Squirrels eat and cache non-native nuts. Birds rarely turn up their beaks at non-native berries. Outside agricultural areas, the story has been the same. Wherever new plants show up, somebody eats it, nests in it, or shelters in it. The Willow Flycatcher (Empidonax traillii), a native bird that is endangered in the US southwest, is now dependent on the non-native (and much maligned) Saltcedar tree (Tamarix sp.), which has led to disagreement between bird lovers and Saltcedar haters.

For many more examples, go to the US Department of Agriculture’s, “Fire Effects Information System,” and look up a non-native plant. Despite the site’s name, it contains far more than information on fire effects. Its detailed plant profiles list animals and insects that use the plants for food and shelter, describe the conditions where the plant thrives, and details of its life cycle, all based on scientific documentation, with oodles of citations.

If we snapped our fingers today and made all the non-native flora disappear over night, we'd have a lot of starving, homeless native fauna tomorrow. That's another fact.

So, instead of seeing a non-native plant as a discrete, disconnected entity, we need to recognize that, for better or for worse (or for neither), that plant is now a member of the community where it lives. It's a different community, but it's still a community. Recently, biologists coined the term, "novel ecosystems," to describe such communities, and have begun taking them seriously as sites for ecological study.

As foragers, we should acknowledge the existence of the new communities around us and respect their active relationships, since our harvesting activities have potential impact on them, as they do anywhere. We return here to the concept of "asking permission." Before cutting that entire patch of St. Johnswort down to the ground when you harvested it because it's "invasive" did you ask the plant first? Did you give any consideration to the pollinators who visit it, the spiders who spin their webs in it, or whoever eats the seeds? What about its role in ecological succession, in preparing the way for the next wave of plants, many of whom might well be native?

(On a side note, I know this is a big ask for some people, but we need to stop using the word, “invasive.” The term is too loaded to be useful. Its inescapably negative connotation ends any meaningful observation or discussion before it can even begin, leaving no room for exploring the role, history or actual attributes of the species. Starting with that villainous label is like putting on a blindfold. It’s not a way to understand—and learn to respect—an ecosystem as we find it.)

If you are completely convinced that the St. Johnswort doesn't "belong" there beside that logging road, then what will you do to change the environmental conditions so that native species will be more at home? How about decommissioning the road? Shutting down the timber operation it serves? Undamming the river running beside it? I’m not being sarcastic. I'm totally in favor of decommissioning roads, shutting down timber operations and undamming rivers, and I'll be your ally in such campaigns, even if our motivations are different.

In the meantime, I also love St. Johnswort. Personally, I just love plants, regardless of their origin. I don't hate any of them, and I believe they all deserve respect as living creatures. That’s why I say: We should always seek permission.

“Yeah but what about —?” I can hear some readers insisting, and naming their favorite non-native to hate. “That one is totally bad!” My response: Are you sure? Have you honestly investigated this plant and its role, or are you just going on reputation? Are you only perceiving harmful effects because that’s all you’re looking for? Interactions between a particular plant and its neighbors, both flora and fauna, can be complex and subtle, which is why I repeat: We should always seek permission.

But shouldn't we try to preserve native plants? Of course! This will be accomplished primarily by protecting any current, intact (or more or less intact) native ecosystems that do still exist. This will mean prioritizing native habitat over human "development" which ultimately requires putting the brakes on techno-industrialism. That, I'm afraid, is where many people lose their appetite for "conservation."

Centuries of agriculture, fossil fuel extraction, urbanization and all their attendant pollution have been horrific enough, but now new places are under the gun that were so far largely spared because they weren’t suitable for those activities. I'm thinking of the Sage Brush steppe in Nevada and Oregon at risk from lithium mining for batteries, or the desert in the US Southwest imperiled by solar and wind farms, or the Oak and Manzanita woodland in Arizona threatened by copper mining for all the new power lines required by "green" energy projects. These places are full of native flora and fauna who need our help.

All in all, being serious about protecting nature looks a lot different than what we as a society have been doing so far.

Cultural factors

This essay has gotten long enough, but briefly: We must also ask ourselves questions about what kinds of cultural influences motivate us to reflexively take such a dark view of "non-native" plants.

• Xenophobia—an irrational fear of “the other”—is a firmly ensconced Western trait going back at least as far as the Crusades. It’s telling that the increasingly venomous rhetoric about "invasive species" over the last couple decades has tracked with the so-called War on Terror and heightening anti-immigrant vitriol.

• Our fundamental frame of reference for plants is as agriculturalists, for whom there are good plants (crops) and bad plants (weeds). While this has practical application in a field or garden plot where we have a small cast of characters and the vital goal of feeding ourselves, it is sorely lacking as a way of perceiving and comprehending inter-plant interactions in an undomesticated landscape. A backyard raised bed where weeds overcome your vegetable seedlings is not a model for understanding the interplay between native and introduced plants everywhere else.

• We perceive the concept of the “survival of the fittest” through the lens of our own social structure, which is heartless capitalism based on cutthroat competition. We underemphasize cooperation and mutualism as forces in inter-species relationships and in evolution (see Kropotkin), often because we aren’t even looking for them.

• Our perspective of nature as stable, with everything in its appointed place—and in which change is anomalous—is a Bronze Age notion handed down to us through Abrahamic religion. Now we know that continents move, that Ice Ages advance and retreat, that climate varies from era to era, that volcanoes and meteors can cause extinctions, and that the ranges of plants and animals have always been in flux in response. The human species evolved in Africa and radiated out in pulses related to such events. That is, now we know that the “natural” state of nature is one of ceaseless transformation and constant adaptation, in both the long term and the short term, and that change is the rule not the exception.

Some sincere introspection, both individual and collective, could help us to see past these cultural influences, and to perceive the other-than-human world more as it is and less as we judge it to be.

We foragers, herbalists and wildcrafters have important, meaningful choices in front of us in this rapidly changing world. We can start by putting less emphasis on the subject of "native" vs. "non-native" and instead striving to understand—and respect—the novel relationships that have emerged, and are still emerging, from our historic and ongoing impacts. This is a time to expand the scope of our ethics, not to dismiss them.