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, […]
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 […]
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 wide-spread and aggressive weed is native to Armenia and Northern Iran. It is considered an invasive species in many parts of […]
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, […]
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 1900s through ballast water from a ship. This plant is native to Europe and Asia […]
What is Herbicide Residue? In recent weeks, the Oregon Dept of Agriculture announced the discovery of contaminated soil and compost materials from an herbicide known as clopyralid. This contaminated material was distributed to gardeners in the region causing significant damage to garden plants and landscapes. This unfortunate event helps to raise awareness of the persistence […]
It is National Pollinator Week! Join all of us here at the WeedWise program in celebrating our native pollinators. June 22-28, 2019 has been designated as National Pollinator Week and there are activities going on here in Oregon and across the country! Summer is here and the weeds and wildflowers are blooming all around us. […]
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 […]
