Japanese Knotweed (Fallopia japonica) on May 8, 2008
Submitter has sample
Description of specimen
Large stand of plants that appear to be similar to bamboo. Stalk of plant is reddish green with knee joints at various lenghts. Leaves are green and triangular shaped. Tallest plants are about 8 feet high. Plants have not bloomed yet.
Commentary
Expert Reviewer
Tania Siemens
WISE Program Coordinator (Watershed and Invasive Species Education)
Oregon Sea Grant Extension
Oregon State University
tania.siemens@oregonstate.edu
541-914-0701
Thanks for reporting knotweed. Yes, this is a very aggressive invader that is taking a foot hold in Oregon. Unfortunately it is quite abundant in the Portland area. I would recommend controlling your patch before it spreads further. You can consult the following link for control guidlines. http://tncweeds.ucdavis.edu/moredocs/polspp01.pdf
You may also want to find out who owns the adjacent property to inform them of the problem and perhaps offer to help them control it.
Good luck!
Tania
The Nature Conservancy EDRR Program Coordinator
Tania Siemens
May 9, 2008, 6:03 a.m.