Wednesday, April 09, 2008
Satan in the Form of a Plant
I had never heard of Japanese Knot Weed prior to moving into the city, neither had my coworker in this gardening project, Evan. Evan was a farmer on a CSA and other organic farms in the state of Oregon prior to moving to Pittsburgh to go to seminary. He also lived on a farm growing up in Meadville PA. Let me put it bluntly, knotweed is evil. It will completely infest an abandoned lot in a city in just one season. If you leave a plot of ground in the city un-mowed it will begin sprouting up and will soon be unmanageable. It grows to be up to 8 or more feet high, in one season, and it's roots run deep. According to some websites I've found it can lie dormant for more than 20 years if you cover it to try to kill it, it can withstand many pesticides, it can penetrate concrete, a small piece of it's root left in the ground will put up dozens of shoots. Really, this stuff seems impossible to get rid up without using strong herbicides.
Here is our plan to begin eradicating it from the land we hope to farm in coming years. Given that none of us has a pesticide applicators license (and I don't anticipate getting one) this is my plan for now, based on what I just read.
1) find the smallest patches (fifty stems of less from last years growth) and dig them out throroughly. collect all plant material, especially roots, to be burned in the testing fire of our gardeners' wrath! ha this could be a good project for a crew, and maybe we could tackle larger patches as well.
the crew could dig patches, and carefully sift roots out, trying to keep them as intact as possible, so as not to spread the knotweed
2) the larger patches we should mow/chop frequently all summer- 2x a month? While we do this, we should continue to watch for new, small patches and dig and burn them.
3) in the fall, we can spray the plants with 5% (or stronger!, if we can get 10-20%) acetic acid---vinegar! After spraying, the patches can be covered with tarps, plastic, cardboard etc.
and this may be an ongoing strategy.