By Joshua Smith

We Americans have been conditioned to see everything in black and white. Unfortunately, nothing is as simple as that. This misleading attitude has resulted in endless conflict based on minimal information, often superficial and rarely complete. Everyone is taking a side and preparing for battle, and blame is spewed out in all directions, while the underlying reality is ignored. In the end, everyone loses and the truth remains as obscure as before.

If the debate on exotics vs. natives is conducted in the business-as-usual manner, we can expect endless conflict rather than enlightened results. On the other hand, if we approach this debate open-mindedly, putting aside our egos, we all might come away truly informed and empowered. There are underlying core issues here that are often overlooked in this debate. In addition, things are not always as they first appear to be. If we look for the negatives of any plant, we will find them. If, on the other hand, we look only for the positives in the same plant, we will find them as well. Simplistic concepts based on dualities like right and wrong just won’t do; truth is both simple and complex at the same time. My hope is that we call come away from this debate more intelligent than when we arrived.

My professional work with plants began in 1971 when I started an organic culinary and medicinal plant business. We both grew plants and wildcrafted them. It was at this time that I began looking at the way different species interacted with each other. Ecologists look at this as plant associations, Permaculture refers to it as guilds, but back then it was called companion plants and came from biodynamic agriculture. Even today, our understanding of this subject is primitive.

My herb business was short-lived, so I started an organic landscape maintenance business in 1973 or 1974 that lasted fifteen years. In 1978 I became a landscape contractor and began designing organic, functional, interactive landscapes. My specialties were (and still are) edible landscapes and native landscapes. In 1980 I got my first restoration forestry job, where I included ecological rehabilitation methods and re-introduced indigenous understory plantings. In the same year, I began designing homesteads and farms, and that continues today. In 1988 I moved to New Mexico and helped establish Seeds of Change, the first all-organic seed company. In 1989 I was invited to Santa Fe to spend a week living with Bill Mollison. Soon after, I was given a scholarship for a Permaculture Design Course. Since then, I have taught Permaculture in five states, and designed Permaculture projects in six states. Some of these I installed and established as well.

All through these many years, I’ve dealt with weeds, several tons of them I expect. I like to eat some of them, and I’ve used them medicinally. And of course, I have tried to control them. Indeed, I could fill a book on all I’ve learned about weeds both good and bad. This long-time intimacy with weeds has given me some perspective on the subject, I believe.

There are no shortages of definitions on what constitutes a weed. To the big chemical companies, a weed is simply a plant someone wishes to get rid of. They are only too quick to jump on the conservation bandwagon to control weeds. It makes little sense to me to use expensive, toxic chemicals in an effort to restore the environment. In this case, the cure is worse than the problem.

As for myself, I have no handy definition of what a weed is, nor do I feel a need for one. In general, I find that weeds are invasive only in disturbed places where the ecosystem was first degraded or destroyed by human activities. In many situations, particularly agriculture and ranching, many of the “weeds” are native plants competing with exotic (non-native) crops or pastures. More than once, I’ve seen weed species nursing native plants that otherwise had mostly disappeared. The majority of our invasive alien weeds hitchhiked here from other continents on pant cuffs, dress hems, or livestock. In other words, they were introduced unintentionally, unknowingly.

In pre-Columbian days, California’s valleys were densely covered in colonies of bulbs and perennial evergreen grasses. Beautiful flowering bulbs like Brodiaea, Triteleia, Dichelostemma, Allium, Camassia, and Calachortus bloomed everywhere. When the bulbs were out of bloom, the evergreen grasses kept the landscape a lush green. Today the bulb colonies and native grasses have all but disappeared, replaced by cool-season annual Old World grasses introduced with cattle. These annual grasses die as the weather turns hot and dry. Drive through much of California’s rural areas today in summer, and you’ll see endless acres of dead straw-colored weed grasses, blanketing valley and hillside.

The pre-Columbian people of California are principally through of as hunter-gatherers, but they were much more than that. Like many other North American indigenous people, California’s tribes farmed the ecosystem in a subtle but productive way. They were highly intelligent eco-stewards. For example, they used all the bulbs mentioned as food, and others too, like their multi-purpose Amole which was used as food, medicine, soap, cosmetics, glue, and for brush making. European ranchers saw the natives as ignorant savages and drove them from the land. The Europeans thought the California landscape was perfect for cattle, and overgrazing that favored the introduced annual grasses soon followed. The bulb colonies collapsed and died out when the tribal people were denied access to the land. For countless millennia, these people harvested the older bulbs and put the immature bulbs back in the soil to grow. When this practice was stopped, the bulbs overgrew themselves and literally crowded themselves to death.

We humans have altered the natural landscape far more than we can imagine. It might be said of us of European extraction that we are a weed species ourselves. As I’ve said, where weeds are increasing rapidly in a natural area, they are typically just the tip of the iceberg. The factors and their degrees of influence that are degrading or have degraded the site should be evaluated. Are the invasive weeds performing services like improving and protecting the soil? Disturbed or degraded soils are where weeds are found in abundance. Some weeds grow on fertile soil and others on infertile soil. Some thrive in drought; others are adapted to moist or even soggy soil. Regardless of the kind of niche that is degraded, there are weeds for it.

In order to establish natives to replace weeds, the soil must be able to favor them. This may require more humus and a dramatic increase in beneficial soil organisms like microbial communities and fungi. There are often many steps going from weeds to self-reliant native plants. Eradicating the weeds alone can be good or bad depending on a number of factors. Even eradicating the weeds and then planting natives can often fail. Restoring a damaged habitat requires a sound ecological plan and a carefully managed operation with follow-up. Such planning requires our consciousness to enter the complex web of relationships that allows ecosystems to function sustainably.

When I lived along the Huerfano River in the Colorado Rockies, the highly eroded soils had long been overgrazed. Even along the river’s edge, the riparian trees and plants were entirely missing beside much of the river. Just below my house, close to the river, was a grove of Russian olives, a tree one always finds at the top of invasive weed lists in the western interior. Under these Russian olives was found the only lush colony of native grass and herbs anywhere around. A closer look revealed dozens of native willow and cottonwood saplings as well. This grove of Russian olives was the only productive site of vigorous native riparian plants anywhere around. Many times I’ve seen this “weed tree” growing on overgrazed, highly eroded sites where no other tree would grow. Obviously, eradicating this tree for conservation purposes can at times be counterproductive.

On the other hand, I’ve seen a plot of over 1000 acres of nearly solid star thistle on overgrazed land in southern Oregon. Pity the poor cow or person who stumbles into a large colony of star thistle. Cows get in there and get so wounded they can’t walk; they simply collapse and die of thirst. In the Santa Cruz Mountains of California, I started seeing star thistle along the edge of Bear Creek Road, deep in the forest. Later I was told that some fellow through it a pretty plant with its yellow flowers and had introduced it intentionally. Today California claims over 14 million acres are infested with star thistle. In portions of the Gila Valley in southwest New Mexico’s Gila River headwaters, large colonies of alien horehound carpeted the ground; anyone or any creature passing through it comes away with dozens of sticky seeds looking to expand horehound’s dominance over the landscape. Below in the riparian corridor, the adventive Johnson grass grows thick and lush. Only large old trees are seen along the river as cattle eat all the young saplings. When the old trees die, there will be no more trees.

Throughout the West, I have fought thistles and bindweed, two of the most difficult weeds. The landscape plant English ivy smothers everything in its path, even strangling native and ornamental trees. In my garden, however, I encourage purslane to cover any bare ground, and I leave a smattering of Malva, pigweed, and lambsquarters to pull up minerals that my veggies cannot reach on their own. Only a few strategically sited weeds do I allow to seed. Either I lay these weeds on top of the beds when I pull them, or I eat them. The purslane is rich in omega-3 fatty acids, Malva is one of the richest sources of beta carotene, and pigweed and lambsquarters provide minerals, good for the soil and good for me. These weeds are called camp followers because they follow human migrations almost anywhere, as they have at least since the last ice age receded. They use the disturbances we make on the land as their habitat; they are close associates of humans and have been for a long time.

In general, it is bad development, bad agriculture, bad forestry, bad ranching, and bad mining that are the biggest problem. The weeds are simply indicators of the problem. Perhaps weeds are simply opportunists, or maybe large colonies of poison oak or star thistle are nature’s last ditch effort to protect the land from further human destruction, guardians against a species that has run amok.

Many of the jobs I’ve had over the years are in forests or have riparian corridors or both. My first concern as a designer-planner is to maintain the site’s ecology and if needed improve it if I can. When looking for potential economic plants for the site, I look at natives first. There is a strange phenomenon in landscaping where we grow plants native to the Eastern United States, Europe, and elsewhere here in the West, and landscapers and gardeners in the East or in Europe grow native plants from the West. Indeed, many western native plants of ornamental value are not available even in native plant nurseries on the West Coast but can be found in eastern nurseries and even European seed companies.

In my view, the landscape and nursery industry should shift their focus and provide and use far more local ornamental native plants. Secondly, these industries have limited their mission to simply provide plants (primarily exotic) that have pretty flowers or foliage on plants that are easy to grow. In this era of an overheating planet, these criteria should become obsolete. Many exotic plants are not weeds; that is, they won’t naturalize, or if they do they are not invasive. In addition, they may provide ecological services (nitrogen fixation, mineral accumulation, habitat for beneficial insects and pollinators, etc.). Indeed, numerous non-invasive alien plants supply us with food, medicine, fiber, and even hydrocarbons for biofuel. Useful native and alien plants are critically important for economic relocalization efforts to moderate global warming.

In light of the dramatic impact global warming will have on our planet and its ecosystems, not to mention our own survival, economic relocalization is seen as an essential strategy for ending our petrochemical dependency. Local food production is high up on the list of relocalization efforts. Biointensive farms that are 200% or more productive than industrial agriculture, and in particular Permaculture farms that can be several times more productive than even some biointensive farms, are crucial, particularly in and around urban-suburban communities. Many if not the majority of the plants on our farms are of foreign origins. Occasionally some might escape cultivation, but only rarely, if at all, are they invasive in a healthy natural system. (From time to time, I’ve found individual apple trees, struggling to survive in forests.)

As a Permaculture designer, the first thing I look at is the existing ecosystem, if there is one, on the site I’m working on. Whether there is one or not, useful native plants that I can include in the plan are among the first plants I choose, whether I’m doing an edible landscape or a farm. In addition, I arrange plantings of both native and exotic plants in guilds that supply ecological services to one another. If I have a problem with invasive weeds to correct, I first look for any potential values. For example, they may make good compost, or, as I have done with St. Johnswort, they may be harvestable for the marketplace. Some weed plants are medicinal; some are edible; some may supply fuelwood, craft materials, or other useful products. Some will feed the goats, sheep, or geese. Weeds can sometimes prove a valuable resource even when you’re controlling them.

Let me end with one of my favorite adventives, Hesperis matronalis or sweet rocket. This is a landscape/garden perennial that has naturalized in many places. In my experience, sweet rocket is non-aggressive, appearing in isolated clumps occasionally in wild places. I’ve only found it livening up disturbed sites. By all means, weed it out where appropriate, but first collect the seeds to take home with you. Sweet rocket’s lovely lilac-purple flower clusters are beautiful and will perfume the nights with their fragrant ambrosia. In addition, its flowers, young leaves, and seed pods are edible, having a spicy mustardy flavor. The seeds are good eaten sprouted. You may run across a clump of sweet rocket in Lane County that’s naturalized, but it’s not common. In Colorado’s Front Range, it’s also naturalized here and there. Nevertheless, the state of Colorado has banned it. Only once did I find an area in Colorado where it had escaped; these were disturbed sites where it grew only in small patches and appeared to be competing with nothing. As I said, it’s a complicated subject and I’ve just scratched the surface.

 
Contact Joshua Smith at Ecoscape Environmental Design, 1380 W. 17th Ave., Eugene, OR 97402, (541) 344-4378.
 

 

back to articles [0]  back to main event page [0]