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Tree-of-Heaven Falls Far from the Name

If you start looking around Clackamas County, it won’t take you long to find the invasive tree-of-heaven (Ailanthus altissima).  This state-listed noxious weed is increasingly more common in many of our urban areas where it flourishes.  Tree-of-heaven seems right at home in alleys, roadsides, railways, vacant lots, that crack in the sidewalk.  Very large trees […]

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Knotweed

September’s Weed of the Month: Knotweed

September is the Time to Control Japanese Knotweed Japanese knotweed (Fallopia japonica) has been called a “nightmare” and a “botanical bully,” and is one of the 100 worst global invaders. These characterizations give you a pretty good idea of just how unwelcome this invasive weed is in our community. Japanese knotweed is fast-growing and hardy, […]

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August’s Weed of the Month: Puncturevine

Puncturevine (Tribulus terrestris) is aptly named! This invasive weed has spiny seed heads that can easily puncture a bike tire, inflatable raft, animal paw, or footwear. Be on the lookout because it is beginning to make its way into Clackamas County from eastern and southern Oregon. Also known as “goathead”, puncturevine is native to southern […]

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Tansy Ragwort Poisons Livestock and Neighborly Relationships!

Tansy ragwort has long tormented rural landowners who graze livestock. Horses and cows are especially susceptible to this poisonous weed. In open fields, grazing animals will generally avoid eating tansy ragwort, but in heavily infested pastures they may have few other options.  Contaminated hay is particularly a problem because it becomes impossible for feeding animals […]

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pollinator header

It is National Pollinator Week!

It is National Pollinator Week! June 21-27, 2021 has been designated as National Pollinator Week in Oregon and across the country!  Join the WeedWise program and other organizations across the country in celebrating our native pollinators. Summer is here and the weeds and wildflowers are blooming all around us. This burst of summer color also […]

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Phslider

June’s Weed of the Month: Policeman’s Helmet

Policeman’s helmet (Impatiens glandulifera) is an invasive weed that grows in ditches, wetlands, and along waterways. Native to India, this fast-growing annual was introduced as an ornamental plant due to its impressive growth and the showy purple, pink or white blooms. Since introduction, it has escaped cultivation to become the dominant riparian vegetation in many […]

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WeedWise Program