Japanese Knotweed has arrived at Dragonfly Farm and war has been declared !!! Japanese knotweed is an aggressive invasive plant that forms a monoculture. It out competes all other native plants until all you are left with is a sea of knotweed. It is a world wide problem, they are fighting it in the UK, fighting it on the US east coast, the mid west, and the pacific coast.

Several weeks ago I noticed that our neighors japanese knotweed infestation had spread to our property line. Our kiko goats will eat it, but they are not fond of it. The bad news is that research has shown that grazing alone is not effective at killing japanese knotweed.

I reluctantly made the decision to use herbicide on the knotweed based on the research available as well as the location and size. The location of the infestation is on our property line and interwoven with a stonewall. The rocks and boulders prevent mowing, the property line issue prevents grazing, and the research indicates that mechanical control is usually ineffective. I decided to try Roundup ( glyphosate ) at the premixed concentration available to homeowners ( 2% ) vs buying concentrate and mixing my own spray. I applied the spray by cutting the canes above the first joint and filling the cavity with herbicide, any canes that were too small to cut and fill I simply applied a foliar application. The site is also the home of several other obnoxious weeds, poison ivy and greenbriar. I was tempted to let loose and go spray crazy, but my better judgement prevailed. As annoying as poison ivy and greenbriar are, they are native and don't represent anywhere near the threat posed by the knotweed.

The best resources I have found so far on knotweed and how to kill it are: http://www.co.clark.wa.us/weed/documents/Dickey%20River%20Knotweed%20Report.pdf

http://tncweeds.ucdavis.edu/moredocs/polspp01.pdf.

In the UK: http://www.cabi-bioscience.org/html/japanese_knotweed_alliance.htm