New group hopes to eradicate invasive plants

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It may seem tempting to purchase rare and unique plants to put in the front yard, but when new species are introduced into an ecosystem, weed specialists say it can create a negative ripple effect.

Take the example of Japanese knotweed, which has overrun streams and creeks in Clark County since the 1970s. Simply mowing down these weeds can help spread its growth even more.

“A space can go from being a woodland area, where there’s shade and things growing along the waterway, to being an open shrub area dominated by knotweed,” said Clark Public Utilities Invasive Species Coordinator Brad Mead.

To counteract harmful impacts of noxious weeds, Clark Public Utilities formed a new community group called Weed Watchers as part of the Eradication Nation program. Plant experts will help educate locals about identifying native and invasive plants as well as offer a platform for people to report their findings, Mead said.

Anyone with access to a smartphone can download the Early Detection and Distribution Mapping System app, or EDDmapS for short, developed by the University of Georgia. The app will download a list of invasive plants in a set location.

For professionals like Mead, it is essential for them to know where invasive species are growing to eradicate them early.

“As the plants multiply and start taking over more areas, it becomes increasingly more expensive and difficult to control and contain their spread,” Mead said.

As people partake in summer activities, like hiking, walking or gardening, they can use the app to report invasive and native plants that will then be sent to area land managers. He said the top reporters will earn prizes, including a Chico’s bag.

Team members from Eradication Nation and the Pacific Northwest Invasive Plant Council will host training virtually for those interested in the program, including information on identifying plants and using the app. Mead conducted the first training last Thursday and will be available on the utility website.

Mead said Weed Watchers relies on community members to spot problem areas, many of which wouldn’t have been caught by the utility otherwise. Those interested in the program can email Mead at bmead@clarkpud.com to register for free.



“It empowers anyone with a smartphone and a little bit of interest in our local landscape to protect these environments we love,” said Dameon Pesanti, the media specialist for Clark Public Utilities.

The utility has documented more than 100 invasive species in Clark County, with many more still left to find, Mead said.

The vast majority of invasive plants introduced to the county’s ecosystems came from the nursery industry that sold different species to gardeners. Once the plants escape cultivation, they start growing in wild places.

“They don’t have those pathogens and pests that the native plants do, so they will be able to thrive and have an unfair advantage,” Mead said.

Agricultural producers also spend hours upon hours to keep weeds at bay because they can reduce profits.

Mead recommends speaking to someone from Eradication Nation before removing invasive weeds themself. Some plants, like hogweed, have toxins with negative effects on humans. It produces a dangerous sap that sensitizes a person’s skin to the sun. The easily spread toxin leads to severe burns and permanent scarring.

“If they’re looking to plant something on their land, just choose native plants,” Mead said.

If the ecosystem were a full circle, weeds would be an intersecting line that disrupts the habitat’s flow of operation, Mead said.

Birds require an abundance of insects in order to feed their young and to create the next generation. Native insects often cannot eat the invasive weeds because the plants produce different chemicals, resulting in fewer bugs for birds to prey on.

“The bugs keep finding ways to circumvent these defense mechanisms, which might sound like a pest to a gardener but they end up actually being critical to the ecosystem,” Mead said.