It has become clear that our overuse of pesticides, fungicides, herbicides, and all the other -cides are harming life, including us humans. Herbicides in particular have earned a damning spotlight, deservedly so. I remember how shocked I was when I first read Whitewash: The Story of a Weed Killer, Cancer, and the Corruption of Science by Carey Gilliam. After finishing that book, I decided I would not use herbicides again.

Exploring Alternatives to Herbicides

But then I began working to replace lawns and fields with native meadows at Leaf & Limb – we call these Piedmont Prairies, which is a form of ecological restoration. To perform this work successfully, it is vital to clear the existing lawn and weeds. I used occultation (dark tarps, black plastic, and cardboard) to deprive plants of light, solarization (clear tarps) to cook the existing vegetation underneath, and all-natural herbicide alternatives like EcoBlend.

The tarps and plastic, even when weighted down, were battered by winds, tore easily, and ended up in the trash all too frequently. With cardboard, every piece had to be weighted down, and even then they often went flying during summer thunderstorms. I tried adding a thick layer of arborist wood chips on top of the cardboard, but then had to remove all of them before sowing the prairie. It was a tremendous amount of work, especially given the small size of the space.

While the herbicide alternatives often worked well for small spot applications, they were less effective for large areas due to cost, the number of required sprays, and their inability to kill many grass and weed species. I did achieve some success in a narrow range of constraints, such as a small yard with tame weeds that could be micro-managed across multiple growing seasons. But for most sites, I was not able to kill the vegetation. Bermudagrass, for example, was a special challenge – these approaches did not even touch it. This made it hard, if not impossible, for the Piedmont Prairie to establish.

Reconsidering Herbicides for Ecological Restoration

As my installations were stalling, I found myself in a quandary. Removing invasive trees, shrubs, and vines – another form of ecological restoration – proved to be even more challenging for certain scenarios. While there were many species that responded well to procedures such as mowing, girdling, smothering, severing, and pulling (starting to sound like Waffle House hashbrowns and containment), others stubbornly persisted. What to do?

I began questioning my viewpoint. Is a “no herbicides ever” approach really the right one? I began diving into the research and realized that my thinking was too binary. I now believe that, in the context of ecological restoration, herbicides – and especially glyphosate-based herbicides – can be a helpful tool.

Let me make two very specific notes before we proceed. I developed a framework that focuses on the positive and negative impacts of incorporating glyphosate into some ecological restoration projects, viewed in three important, intertwined contexts. Let’s examine these and then discuss ways we can mitigate the risks.

Evaluating the Impacts of Glyphosate-Based Herbicides

Ecosystem Health

The positives are clear – GBH application is a very effective method for clearing lawns, weeds, and stubborn invasive plants. Removing these problematic species creates a space where new plants can thrive, and by replanting the area with native trees, shrubs, and Piedmont Prairies, we create a richer, more resilient ecosystem that benefits everything from butterflies to bees and from hawks to humans.

On the negative side, we need to consider what happens when glyphosate ends up in the soil, where it poses a threat to soil microbes and plant roots, and thus the very foundation of a healthy ecosystem. Fortunately, glyphosate binds readily and tightly to soil particles. Once this occurs, it loses its herbicidal properties and is not taken up by plant roots.

As for antimicrobial activity, studies have demonstrated variable but small impacts on soil microbial diversity and biomass. Soil microbial communities generally recover quickly from GBH applications, especially when they are not subjected to it for extended periods of time. Luckily, ecological restoration projects typically only require one to three GBH applications. But when they are subjected to GBH treatments repeatedly for extended periods, soil microbial communities do incur damage. This is why I’m still very much against using GBH and all other herbicides as part of ongoing landscape maintenance.

Human Health

The acute toxicity of pure technical-grade glyphosate for terrestrial animals is very low. However, certain compounds commonly used in the formulations of GBHs, such as the widely-used surfactant polyoxyethyleneamine (POEA) found in Roundup and other common formulations, can be more toxic than glyphosate itself.

We must also take into account the risk of glyphosate being washed by runoff into nearby bodies of water, where it could harm aquatic life. Evidence suggests that aquatic animals may be even more sensitive to the effects of formulations that contain POEA. In addition, glyphosate has the same powerful effect on aquatic plants and algae as it does on terrestrial plants, causing major disruptions to aquatic ecosystems. As a result, extreme care must be taken to avoid allowing GBHs to wash into local waterways.

As for the potential risks to human health, the mental and physical benefits of surrounding ourselves with a healthier, more vibrant ecosystem are real. But so are the potential negative impacts of glyphosate on our bodies. While the acute toxicity of glyphosate to terrestrial animals, including mammals like us, is low, the risks associated with long-term exposure are more concerning.

Some research has identified associations between the use of GBHs and a variety of health conditions. In many cases, there isn’t sufficient evidence to conclude that glyphosate itself is the underlying cause – toxic additives such as POEA are also possible culprits. In particular, a possible link between the use of GBHs and non-Hodgkin lymphoma, a form of cancer, has been the subject of debate. While most internationally prominent regulatory agencies have concluded that glyphosate is not a probable carcinogen, a dissenting 2015 assessment from the World Health Organization has fueled ongoing controversy.

Carbon Footprint and Waste Output

The third and final component of this framework is the positive and negative outcomes in the context of carbon footprint and waste output. Let’s say we skipped the GBH and stuck with laying down tarps. Creating plastic tarps requires fossil fuels, which must be extracted from the ground, processed, and transported to the plastic production facility. Once the plastic has been produced, it is packaged in yet more plastic that goes through a similar manufacturing process. Then the product must be transported using trucks that burn fuel, consume rubber tires, and emit pollutants. Finally, the plastic becomes waste and ends up in a landfill, which requires more energy for transport.

What about all the energy required to fuel various non-GBH methods of lawn, weed, and invasive plant removal? Work requires energy to power humans and machinery. Energy requires extracting fossil fuels from the ground for the machines and producing food for the humans. Growing food involves fertilizers, herbicides, more machines, and energy consumption. Food also requires transport, refrigeration, and human labor. What about driving to and from a site multiple times to do what a GBH can do in one or two visits? We burn fossil fuels, emit pollutants, and so forth.

On the whole, I think that the appropriate, responsible, and limited use of GBHs within the context of ecological restoration can help us to leave a site in better ecological shape than how we found it. We take one step back for two or ten steps forward. We can reduce and very nearly eliminate exposure and thus health concerns by wearing necessary protective equipment specified on the label, at a minimum.

In the context of carbon footprint and waste production, the use of GBHs generally has a lower carbon footprint and generates less waste output as compared to alternative options. To be doubly sure, I consulted with experts from around the country who also care about the well-being of this planet. The consensus was nearly unanimous: in the context of ecological restoration, GBHs can be a helpful tool.

Best Practices for Mitigating Risks

Here is a summary of best practices to mitigate risks associated with GBHs, some of which were mentioned previously and some of which are new. We follow these best practices at Leaf & Limb, and we would advise others to do the same:

1. Limit GBH applications to one to three times per project, rather than using them as part of ongoing landscape maintenance.
2. Wear the necessary protective equipment specified on the label, at a minimum, to reduce exposure.
3. Carefully monitor application to avoid drift or runoff into nearby bodies of water.
4. Combine GBH use with other methods, such as mowing, girdling, or smothering, to minimize the amount needed.
5. Replant the area with native species as soon as possible after treatment to establish a healthy, diverse ecosystem.
6. Monitor the site for regrowth and apply follow-up treatments as needed, but avoid repeated, long-term use.
7. Explore alternative methods, such as occultation or solarization, for small-scale or less stubborn vegetation.

While we can never reduce the risks to zero, these steps go a long way towards preventing negative outcomes. In the end, I traded an old binary outlook for a more nuanced framework that allows me to navigate multiple scenarios with greater truth. Is it the right one? Yes, for now. But per usual, I will trade my old ideas for new and better ones when I find them. There may be a day when I learn new practices and better frameworks that surpass the ones I use now. I look forward to that day because I enjoy learning, evolving, and becoming a better version of my former self.

So, if you’re looking to remove invasive trees and use the timber responsibly, I hope these tips have been helpful. Remember, you can always reach out to the team at timber-building.com for a free quote or tree-related advice. We’re here to help you navigate the complexities of ecological restoration and responsible timber use.