Japanese Knotweed Control Program
Japanese Knotweed along tributary to Crabtree Creek: note white flowers
The South Santiam Watershed Council is leading efforts to inventory and treat Japanese knotweed in the Crabtree Creek watershed. This noxious weed is fast growing and invades river and creek banks. Knotweed displaces native vegetation, greatly reduces fish and wildlife habitat, and harms our economy by taking over valuable land and lessening our recreational opportunities.
Knotweed can be found in moist soil or river cobble, in full or partial sunlight. It spreads down waterways in flood events, or when contaminated soil is spread accidently. Root fragments as small as 1/2 inch can start new plants!
What Does Knotweed Look Like?
Knotweed grows in dense stands, up to ten feet tall. It looks similar to bamboo, with bright green leaves 1-8 inches wide. Knotweed starts
Click map for larger image
growing in April, achieving full size by July. At the end of summer, knotweed will have spikes of small, white flowers. In the winter, the knotweed lies dormant with dead, brown stems standing.
If you think you have Japanese Knotweed growing on your property, and you live on Crabtree Creek or one of its tributaries, contact the SSWC as we are signing landowners up for a knotweed inventory/treatment program. The past four seasons of work have resulted in nearly 100 landowners having their property surveyed for knotweed, and about 18 river miles treated. Eradication is dependant on funding, but we are hopeful that we can control the problem in the coming years.
If you do not live in the Crabtree Creek watershed, but still think you may have knotweed on your property, feel free to contact us and we will discuss management strategies.
Knotweed Treatment
The South Santiam Watershed Council is treating knotweed in the Crabtree Creek watershed with a cocktail of herbicide labeled safe for aquatic purposes. Treatment is usually done towards the end of summer when the plant is drawing in resources in preperation for its winter dormant period. The SSWC uses licensed applicators to conduct treatment. The applicators are required to take every percaution around water and native vegetation. Once an infestation of knotweed is controlled, the SSWC will work with landowners to re-vegetate the area with native shrubs and trees. Native vegetation provides shade for streams, helps stablize banks, and filters out toxins.
Certified Herbicide Applicator Treating Knotweed
Native ferns placed at Roaring River Park after knotweed control
