Japanese Knotweed (Fallopia japonica) on Apr 14, 2014
Submitter has sample
EDRR Status: Local expert notified
Description of specimen
a small patch, maybe 10 square feet (what I can see) of knotweed. It's located behind Forest Heights Apartment building C. The site is at the top of a little ravine through which a small stream travels through. It's a highly impacted site with lots of blackberry and ivy, but the knotweed looks relatively small and seems to have established recently.
Commentary
Expert Reviewer
Samuel Leininger
Clackamas Soil and Water Conservation District
4-County Cooperative Weed Management Area
Columbia Gorge Cooperative Weed Management Area
First thanks for attending our recent Four County Cooperative Weed Management Area meeting. it was great to see a new face.
I also wanted to thank you for reporting this infestation of knotweed. Japanese knotweed is a significant problem invader within Clackamas County. The Clackamas Soil and Water Conservation District is working with regional partners to map and catalog known infestations of knotweed to help prioritize future control efforts.
Unfortunately, the resources required to control this invader are limited in relation to the overall need. We are currently treating a number of knotweed patches at priority sites across Clackamas County. Unfortunately the patch location you submitted is outside of our current priority areas. As such we must rely upon landowners to initiate control on property they own or manage. We currently offer technical information and assistance to local landowners to help them develop a management strategy that is effective for their particular site conditions and needs.
Your report will help us to prioritize future knotweed treatments. So thank you for taking the time to report this invasive species. Please feel free to contact me if you have any additional questions.
For more information please check out the resources provided below.
http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/21809/em9031.pdf
http://your.kingcounty.gov/dnrp/library/water-and-land/weeds/BMPs/Knotweed-Control.pdf
http://www.imapinvasives.org/GIST/ESA/esapages/documnts/polycus.pdf
Again thank you for reporting this invader. All the best,
Samuel Leininger
WeedWise Program Manager
Clackamas Soil & Water Conservation District
221 Molalla Ave. Suite 102
Oregon City, OR 97045
503-210-6006
weeds@conservationdistrict.org
www.conservationdistrict.org
Samuel Leininger
April 16, 2014, 2:38 a.m.