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 […]
Tag Archives | Class B
October’s Weed of the Month: Himalayan Blackberry
The Thorn in Our Side Himalayan blackberry (Rubus armeniacus) 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 widespread and aggressive weed is native to Armenia and Northern Iran. It is considered an invasive species in many parts of […]
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, […]
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 […]
July’s Weed of the Month: Tansy Ragwort
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 1900s through ballast water from a ship. This plant is native to Europe and Asia […]
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 […]
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 […]
October’s Weed of the Month: Himalayan Blackberry
The Thorn in Our Side Himalayan blackberry (Rubus armeniacus) 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 widespread and aggressive weed is native to Armenia and Northern Iran. It is considered an invasive species in many parts of […]
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, […]
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 […]