Knotweed (unknown species) (Fallopia sp.) on Jul 19, 2008

Originally reported as Japanese Knotweed (Fallopia japonica)

Submitter does not have a specimen

Description of specimen

Several shoots are full sized, especially on the yard side of the fence.

I spotted this plant cluster a month or so ago and, a few days later, I saw some lawn care guys clearing all the shrubs and weeds on the street side of the fence. I pointed out the knotweed and suggested they be somewhat careful in the way they dispose of it. When I cycled past a few hours later, I saw them packing up and had reason to doubt they took my suggestion seriously. Now, of course, where they had cleared, there are dozen brand new shoots already several feet tall.

I didn't bother to photograph or take a sample of this plant. It's a large and perfect specimen of Japanese Knotweed just like what I reported in June(see http://oregoninvasiveshotline.org/reports/107) which has been confirmed.

Commentary

A week of so after I reported Japanese Knotweed on Bryant Road (see http://oregoninvasiveshotline.org/reports/107), I noticed that someone had hacked off the shoots about six inches above the ground on the street side of the low fence. Everything on the yard side was left untouched. Now, new sprouts have come up from the ground, doubly vigorous.
Is your office attending to these plants? Or should I assume someone else came and cut those shoots down perhaps after reading my report?

Reporter
July 19, 2008, 9:39 a.m.

Hi Kristin,

Thanks for keeping those reports coming! It is unlikely an agency is attending those plants. Knotweed is so widespread that any control work needs to be prioritized based on its current distribution and proximity to valuable sites.

I will forward your report and inquiry to a local contact person at the Clackamas SWCD. Perhaps they have some knowledge of that site. Also, we are always interested in learning of new locations. Even if they can’t be prioritized right away, having a more complete distribution map is valuable for management decisions. So, thanks again for your reports!

Tania Siemens
OSU Sea Grant/The Nature Conservancy
tania.siemens@oregonstate.edu

Tania Siemens
Aug. 5, 2008, 12:15 a.m.