What are invasive species?
Many people are affected by invasive plant species and noxious weeds, whether or not they realize it. Non-native plants reduce land productivity, destroy helpful native species, and use up valuable resources for growth, such as soil and water. Additionally, these invasive species and weeds could be hazardous to human health, poisonous to livestock, and reduce land value.
Weeds are any plant in a place we do not want it to be. Gardeners, farmers, landscapers and parks managers all have to deal with weeds every day.
Noxious weeds are plants considered harmful to animals or the environment. Some like giant hogweed can make humans sick as well. The Oregon Department of Agriculture works hard to prevent the sale and trading of noxious weeds in Oregon. This helps protect farmers as well as their neighbors in cities and towns. You can learn more about the ODA Noxious Weed list at www.oregon.gov/ODA/programs/Weeds/OregonNoxiousWeeds/Pages/Law.aspx
Invasive weeds can be native or non-native plants. Usually, they are plants from other parts of the world. These plants were brought here for many reasons: to control erosion, to produce more vigorous crops, for their beauty, for medicinal reasons, or even just to bring a little piece of home to a new place. Because our growing climate is so mild, our rain so abundant, and our soils so fertile, these non-native invasive plants can easily take over. They love to occupy disturbed places, that is, places where the native plants have been removed for some reason and bare soil has been left in their place. Some invasive species like garlic mustard even change the chemistry of the soil, killing off beneficial fungi and bacteria, or making the soil chemistry intolerable for other plants to germinate and grow.
You can help stop the spread of invasive weeds!
Invasive plants like blackberry and scotch broom are easy to see in the landscape. They have escaped cultivation (controlled and managed growth in a garden or farm) and have worked their way into natural areas. It costs millions of dollars each year to try to control these weeds in Oregon. Conservationists and the public have reduced our efforts to control these weeds to certain sites – unfortunately, we may never be able to control them everywhere at this point.
But there are new invasive weeds popping up all the time. Our invasive weed list for the Tualatin Watershed can help you know what the newest threats are. You can brush up on how to identify invasive weeds on our website too. We add new Weed of the Month articles just about every month to keep you current.
Become a deputized Weed Watcher in Washington County! This is a great way to learn botany and engage in citizen science. Your school may even be able to help us co-host a Weed Watcher workshop for your community each year. We are also always on the lookout for talented student writers and photographers to help with the Weed of the Month series. Contact Jen Nelson at firstname.lastname@example.org for details!
More great classroom resources on invasive species…
National Invasive Species Awareness Week happens every February. See http://www.nisaw.org/ for this year’s dates and resources.
Oregon Invasive Weed Awareness Week happens every May. See https://www.facebook.com/ODANoxiousWeedProgram for this year’s dates and resources.
Lessons and Activities
USDA Educational Resources
OISC Don’t Let it Loose poster contest
Other Tools and References
Oregon State Listed Noxious Weeds
Oregon iMap Invasives
Oregon Invasive Species Hotline
4 County CWMA
Oregon Department of Forestry Invasive Species
Oregon Invasive Species Council
OSU Extension Watershed and Invasive Species Education
National USDA Invasive Species website
Volunteer Weed Pulls…
Tualatin River Watershed Council
Friends of Trees