Weeds are defined as any plant that is out of place. This is a large part of the problem. The following is an interview with Bob Flasher, who has worked on vegetation management crews in regional parks and in weed control programs in the national parks for more than 20 years. His education is in
cultural anthropology, which will explain some of his interesting and controversial insights into how we define a “good” or “bad” plant.
Invasive Plant News: You have been accused of being a weed-loving tree-hugger and have actually been seen hugging eucalyptus trees. Is there any truth to these accusations?
Bob: I am not now, nor have I ever been a weed-loving tree-hugger. I do cop to loving plants though. The issue is that what plants seem out of place depends almost entirely on someone’s perspective. The National Parks captures this distinction by referring to invasive non-California plants as “plants out of place.” This is to assure us that just because a plant is from another country on our planet, it isn’t necessarily a bad plant, just out of place here.
Invasive Plant News: Are you then recommending that we turn a blind eye to weeds?
Bob: I’m recommending that we tolerate plants we may have considered weeds in the past and focus instead on ones that have never learned how to play well with others. There are many good reasons for doing so. One is that it can save a load of money on weed control. Another reason is that by focusing our efforts on plants that are the most invasive–not every non-native in sight–there is a chance that we will control them. Yet another reason is that it is better karma to tolerate, accept, or even appreciate differences. Martin Luther King Jr. reminded us that “We will either learn to live together as brothers or perish together as fools.” This may apply to plants from different countries as well.
Invasive Plant News: You’ve got to be kidding, right?
Bob: Not really. Here’s one example. The California Native Plant Society defines native plants based on plant communities that have existed in California since the last ice age. But during the ice age, the only native plants in most of California were much more tolerant of cold. As the planet warmed, other warmer-climate-loving plants invaded and are now the ones we call natives. As the ice melted and sea level rose over 200 feet, many of the native plants at that time were overrun by seaweed, kelp, etc. Does this make these marine aquatic plants weeds? So where exactly to we draw the line on what is native and what is exotic? And isn’t that line based more on a climatic or geological time frame than on what has adapted well and supports local wildlife without unduly impairing “native” plant communities?
Invasive Plant News: What about the plants that were introduced by humans and didn’t invade on their own? For example, do you consider eucalyptus “plants out of place” or weeds?
Bob: It depends on your perspective. If a eucalyptus sprouts in the middle of your native grassland or native succulent bed, you would consider it a weed and remove it. If it sprouts on the edge of an existing eucalyptus forest, you might ignore it instead. It’s not as if these trees spread like broom, poison hemlock, pampas grass or yellow star thistle. Except for a few adventurous trees, they are homebodies that stay put where they were originally planted. They provide nectar to hummers during the winter, when other nectar-providing plants are harder to find. They provide habitat for bats that literally hang out under their peeling bark during the daytime. They also provide us firewood, and will continue to re-sprout with more firewood forever. If the sprouts are cut in a timely fashion, we don’t need to split them, just buck them up, let them cure for a year, and light ‘em up in our fireplace on a cold winter night. In addition, eucalyptus draw a lot of water and mulch the ground heavily, preventing a lot of weed species from growing below them. In places like Tilden Regional Park, where fog provides many additional inches of rain every summer, native shrubs grow throughout these forests.
Invasive Plant News: So you’re suggesting that we see the positive side of plant invasions, whether natural or human-induced? Do all plants have a positive side?
Bob: All plants have positive and negative impacts. For example, native plants fight with each other for sunlight and water. This benefits some while hurting others. But all plants, whether we consider them wonderful or weeds, produce oxygen, cool the earth through their evapotranspiration, add organic material to the soil, and provide shelter for local wildlife. What has us all freaked out about weeds is their pushiness. They don’t share well and tend to overrun other plant species more effectively than do other exotics or natives. If this was a case of an American business growing way faster than its competitors, we would point to that as a great success. But we are much more judgmental when we are thinking about plants that do the same.
Invasive Plant News: Can you find a creative rationalization to justify respecting every plant regardless of its harm to others?
Bob: How long do I have? Actually, when it gets way too hard to justify loving a plant, it is a sign that it will soon show up on my weed list. But I always think twice about what will happen if I remove weeds. Two examples: 1. My family owns a home along a river that floods every year. The creekbanks are overrun with ivy. But this ivy helps hold the banks in place during floods. The neighbors, who removed all the ivy from their property, each experienced a huge bank collapse and had to spend over $10,000 to repair the damage and armor the banks with boulders. 2. I spent many years removing eucalyptus forests that were considered a fire threat in the east bay. Those fuelbreaks are now filled with huge, very flammable and more easily ignitable coyote brush and poison oak.
With hindsight, it would have been more effective to remove the lower limbs of the eucs, burn the duff periodically, and maintain the forest. The shady forest would have helped prevent the invasion of natives which have made the fuelbreaks easier to ignite. So in this case involving public safety, it is the native plants that are the weeds. The local parks and municipalities responsible for these fuelbreaks now have to pay goat herders around $700 per acre to keep the brush pruned down to safe levels. The fuelbreak is 13 miles long and has been in existence for over 30 years. Do the math.
Invasive Plant News: You seem to have a very unconventional and laissez faire attitude about weeds. The problem as I see it is this: we generally won’t know whether a non-native “plays well with its neighbors” until it is too late. In our neck of the woods, buckthorn may have seemed like a great shrub for hedges in the 1800s. Now it chokes native woodlands and wetlands and causes over $1 billion a year in crop losses as the primary host of the soybean aphid. Because of globalization, many more non-native plants will be arriving, and we have no idea how they will fit into our ecosystems. Aren’t you advocating less vigilance precisely at the time we need more!?
Bob: I think I’m advocating more fatalism. Due to the hospitable nature of the earth’s Mediterranean climates, I think we are stuck with a lot of plants that have found and will be finding a new home here—at least until the next ice age. In the meantime, as Rodney King pleaded, “Can’t we all just get along?” The answer, unfortunately, is “no.” So I’d agree with you that we have to be constantly vigilant about new invasions. For frame of reference, think about the comparison between plant invasions and human epidemics. Epidemiologists tell us that there is so much international air travel that by the time we realize an epidemic is taking place, it will already have spread everywhere. We can probably expect similar things to occur with plants that have yet to be introduced or invade. This is already true in Hawaii. That is life on earth.
The Golden Gate National Recreation Area handles this challenge by recruiting and training volunteer invasive weed spotters. They walk the trails, forests, brushlands and grasslands, looking for plants on the “least wanted” list. If spotted, the staff immediately eradicates them before they become a much larger problem. So I believe that a combination between more acceptance of increasingly diverse Mediterranean ecosystems in California and quick action to eliminate the most invasive plants will probably be the most effective weed abatement techniques.
Invasive Plant News: We’re afraid to ask another question. Do you have any last words to add before we revoke your credentials?
Bob: Yes. Martin Luther King Jr. pointed out, “We may have come over on different ships but we are all in the same boat now.” This applies to local plants and ones from far away as well. We need to adjust our attitude as much as possible so we don’t make ourselves crazy trying to control the later arrivals. This would be similar to Americans trying to control each historic wave of human immigrants as they migrated from their home countries. It worked for a limited time on a limited basis, but we eventually accepted all the newcomers as part of our society. The vast majority of them, including all of us, have contributed positively to our country. So uprooting us and sending us back to our countries of origin because we are all exotics, wouldn’t make sense. We can’t do this with plants either. All we can do is root out the very small percentage of “plants out of place” that are the plant world’s equivalent of terrorists, bent on the destruction of all others in their path. But we need to do this thoughtfully, paying close attention to unexpected consequences. And there are always unexpected consequences.
Humans seem to have more genetic programming to fear and hate than to love; that’s why we’re living in hell on earth. If we ever want to live in heaven on earth, we need to become more accepting and appreciative of others. I think this applies to plants as well. My credentials are in the mail.