Archive | Weed-of-the-Month

Canada-thistle-slider

March’s Weed of the Month: Canada thistle

Canada thistle (Cirsium arvense) is a widespread invasive weed found in all parts of Clackamas County.  Unlike the many native thistles found in Oregon, Canada thistle can quickly overrun an area and displace native plants, reduce agricultural yield, and create problems for grazing animals when they infest a field or pasture. They also cost a […]

Continue Reading
ivy-slider

January’s Weed of the Month: English Ivy

English ivy (Hedera helix) may conjure up images of cozy, country cottages, but don’t be deceived. This invasive weed can destroy buildings, poison pets, and topple trees. The very characteristics that made it a popular ornamental plant – grows quickly, requires little maintenance, and provides a “no-mow,” evergreen ground cover — are the things that […]

Continue Reading
holly-slider2

December’s Weed of the Month: English Holly

English holly (Ilex aquifolium) is a popular evergreen frequently noticed during the month of December when festive decorators “deck the halls with boughs of holly”.  For many people, the shiny, dark green leaves and red berries of holly are synonymous with the holiday season. This popular plant, however, is not native to Oregon.  In fact, […]

Continue Reading
Spurge-laurelslider2

November’s Weed of the Month: Spurge Laurel

The Scourge of Spurge Laurel Spurge laurel (Daphne laureola) is neither a spurge nor a laurel, but rather an invasive plant in the Daphne family.  This perennial plant has poisonous berries, spreads aggressively in our native forests, and is increasingly being found in Clackamas County. Native to Europe, spurge laurel was introduced in Oregon as […]

Continue Reading
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, […]

Continue Reading
puncturevine-slider

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 […]

Continue Reading
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 […]

Continue Reading
WeedWise Program