2026 February 28 Invasive Species

A great way to ruin a biodiverse ecosystem is to let invasive species outcompete natives. A flourishing wetland can become a Phragmites farm in a season or two if left unchecked. This week, while getting ready for my Pesticide Applicator License Exam, I was reminded of the Invasive Species Management Webinar I hosted with Antonio Zodda of Paradise Natives for Wild Ones Greater Cleveland. 

Check out the Invasive Species Management chat on our Wild Ones Greater Cleveland YouTube channel. This one focuses on woody invasive remediation. We are planning a hands-on workshop this spring or summer once we narrow down a location.

 

I do not take the use of pesticides lightly. In this country, pesticides are so readily available and common, people are very casual with their use; often overlooking the harmful effects they can have on human health and the ecosystem. Even following all the proper protocols, it’s still a poison we are adding to a system. Their use should always be a serious consideration.

As a native plant advocate, pesticides definitely worry me. Many of them were formulated to eliminate the very plants I propagate. It was hard to see several native plants framed as pests to be eliminated in the study materials for the Pesticide Applicator Exam. Marestail Conyza canadensis and Nutsedge Cyperus esculentus are two native species on the list to identify as agricultural pests. I don’t typically grow these plants for the garden, but they do pop up in a planting sometime. Depending on the type of planting, I may leave them or pull them up. Both of them are easy to pull, but timing is important because once they go to seed, you’re cooked. At that point, an herbicide won’t help you either since the seed bank will be full for the next season. I understand with our large industrial farms, they don’t have the time to mechanically eliminate “weeds”. There may be broader issues with the agricultural system itself, but that’s another blog post.

I have read Tao Orion’s research in the book Beyond the War on Invasive Species. It’s powerful and should make us think twice about the benefits of species labeled “invasive”. It’s a whole other post for another day. I understand this point of view, but I’ve also seen beautiful, thriving restored sites that definitely used a one-time application of pesticides. 

People who know me may think I’m fully anti-pesticides, but my actual stance is more nuanced than that. At this point, until something better comes around, there are some reasons to use them. For example, I’ve seen the results of trying to eliminate Tree of Heaven Ailanthus altissima mechanically. When the tree is cut it sends every bit of energy it can into roots to shoot up hundreds more. Then you have a nightmare situation. 

When considering remediation for invasive species, it’s important to weigh all the different factors: know the plant, do the research, consider all the types of options including non-chemical options, consider the timing, then make a plan. 

I’ve read through different Integrated Pest Management Plans (IPMs) from an ecological landscaping perspective and the use of pesticides is all over the place from “use as a last resort” to “use as a preventative measure”. One Maintenance Spec had both recommendations for using native plants as filters for “pollutants such as pesticides”, while it recommended use of pesticides on turf. It seems I’m not the only person with a conflicted opinion of pesticide use. My recommendation is to use them for specific cases, with careful consideration of the benefits and drawbacks for that plant and surrounding plants, following all the protocols.