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 […]
A reality stranger than fiction Straight out of a script from a classic 1950s horror film, a local pond is mysteriously overtaken by multitudes of gelatinous brain-like blobs. These blobs appeared, seemingly overnight to dominate a pond, causing immediate concern from the affected landowner. It is not hard to imagine that if you found these […]
What a difference a year makes It was one year ago that we reported a large infestation of milkthistle (Silybum marianum) growing in a twenty-acre horse pasture outside of Wilsonville. At that time, the WeedWise program was approached by the resident for assistance in helping her to control the milkthistle. As a priority invasive weed […]
The Thorn in Our Side Himalayan blackberry (Rubus bifrons) tantalizes us with its sweet fruits in the summer and tortures us with its prickly vines all year long. Also known as Armenian Blackberry, this wide-spread and aggressive weed is native to Armenia and Northern Iran. It is considered an invasive species in many parts of […]
Do you think you’ve found a noxious weed? Here is how you can get help to identify and report your find! One of the most important aspects in controlling invasive weeds is to verify the identification if invasive weeds before you work to control them. Knowing the difference between an aggressive weed and a common […]
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 […]
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 […]
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 […]
Tansy ragwort (Senecio jacobaea) is an invasive weed with a long and deadly history in the Pacific Northwest. In Oregon, it is designated as a Class B invasive weed. It is believed to have been introduced here in the early 1900’s through ballast water from a ship. This plant in native to Europe and […]
Policeman’s helmet (Impatiens glandulifera) is an invasive weed which grows in ditches, wetlands, and along waterways. Native to India, this fast-growing annual was introduced as a ornamental plant due to its impressive growth and the showy purple, pink or white blooms. Since introduction, it has escaped cultivation to become the dominate riparian vegetation in many […]
