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Solving Stream Problems in Your Back Yard Series - Invasive Plants along Streams

*This is the seventh post in a continuing series on backyard stream management.*

Invasive Plants along Streams

Keeping a riparian (streamside) area vegetated with native woody plants is important for a number of reasons, from their ability to control erosion, to filtering pollutants, to providing habitat for wildlife to name a few of the benefits (read this article on why riparian buffers are important). Invasive plants are a problem because they are aggressive and can outcompete and potentially crowd out native plants. Most invasive plants do not provide the nutrition to wildlife that their native counterparts provide. They get into our landscapes and along streamsides through a variety of means – by hitching a ride on someone’s shoe or by animal dispersal – than take over, creating a monoculture of one plant. They ultimately wreak havoc on natural ecosystems.

For example, Japanese knotweed is common along rivers and streams and grows so dense, it shades out all other native vegetation underneath. With no understory vegetation remaining, bare soil easily washes away by rain or floods. Purple loosestrife, while beautiful, can take over stream banks outcompeting native plants like cardinal flower and swamp milkweed, both important pollinator species. English ivy, while pretty groundcover in our yards, can spread into forests and harm native plants and suffocate trees. Myrtle is another species to try and avoid planting in yards close to wooded areas as it can spread and take over habitat for native plants.

How do I identify Invasive Plants?

In Northeast Ohio, the most common invasive plants that are problematic along streamsides and in wetlands are:

Japanese knotweed
Phragmites
Reed canary grass
Narrow-leaved and hybrid cattail
Purple loosestrife

Invasive plants more of a problem in wooded or flat floodplain areas include:

Asian bush honeysuckle
Glossy buckthorn
Garlic mustard
Japanese honeysuckles
Lesser celandine
Multiflora rose
Norway maple

The Ohio Invasive Plants Council website has great fact sheets for each invasive plant listed above, showing photos for identification and discussing control methods and best timing/seasons for removal.

The Cleveland Metroparks, in maintaining the ecological integrity of their reservations, manages invasive plants as well. Visit their website for more information on why and how to treat invasive plants here: https://www.clevelandmetroparks.com/about/conservation/natural-resources/resource-management/invasive-plant-management

Controlling invasive plants along streams and in sensitive wetland systems is tricky in that you want to protect the water resource from dangerous herbicides that could impact aquatic species and you want to make sure not to harm non-invasive native plants and animals. Certain herbicides are approved for use in and around water resources, but it’s best to consult a landscaping professional for assistance and safe, targeted chemical application if that’s necessary. Each invasive plant has different treatment recommendations, some only respond to chemical treatment while others can be hand pulled manually, like Garlic Mustard, through spring invasive plant pulls before the plant flower goes to seed. It’s also important to know what time of year is best for controlling the invasive plant in question.

When purchasing plants for your yard and garden, do a little research to make sure that what you are buying is native and will help pollinators. Garden centers do sell plants that are invasive, so it’s great to go with information about native plants you like before making potentially harmful purchases. Native plants require less maintenance (like water and fertilizer) because they are supposed to be in our region and can thrive without human interference. A great website for learning more about the benefits of native plants, which ones are good for our region and where to buy them is here: LEAP (Lake Erie Allegheny Plateau biodiversity regional group) https://www.leapbio.org/resources/native-plants

Additional Resources

Invasive Plant Resources:

Ohio Invasive Plants Council website - list common invasive plants in Ohio and has fact sheets on each helping with identification - https://www.oipc.info/invasive-plants-of-ohio.html

Cleveland Metroparks website on invasives/natives: https://www.clevelandmetroparks.com/about/conservation/natural-resources/resource-management/invasive-plant-management

Lake Erie Cooperative Weed Management Area is addressing invasives in sensitive ecosystems through a grant and they have also developed informational fact sheets about invasives here, http://lecwma.wixsite.com/ottawa-cwma/plant-info-sheets (put your cursor over each image to figure out which fact sheet is which).

Citizen’s Guide to the Control of Invasive Plants in Wetland and Riparian Areas, 2003 – while not specific to our region, a lot of the invasives mentioned in this guide are a problem in northeast Ohio. This whole website has a lot of resources.

Native Plant Resources: Cuyahoga Soil & Water Conservation District’s webpage with lots of resources on where to buy native plants: http://www.cuyahogaswcd.org/programs/rain-gardens-native-plants

Blog Author: Claire Posius, Euclid Creek Watershed Program Manager

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