By Randy Helbach, Board Secretary
This article originally appeared in Wisconsin Waterfowl Association’s December, 2020 Newsletter edition.
Japanese Knotweed
I am lucky enough to have been permitted to hunt a private ten acre marshy pond on a farm west of Waukesha for four years. My trade off to hunt the property is picking pumpkins in the early fall and running the cattle through the chute. But now I’ve added a new task… invasive weed control. The first year I hunted I noticed an odd plant that covered about a 1000 square foot area across the field road from the pond. The farmer did not know what it was and neither did I. However, I did some research and found it to be Japanese Knotweed…a highly invasive plant also known as Godzilla Weed!
This is a plant that spreads by both seeds and rhizomes and just loves waterways! It out-competes our native species by completely shading everything out, without any benefit to wildlife. I spoke with the farmer and found the plant came in with some fill he allowed someone to dump in two spots. He was supposed to come back and spread it out… but luckily never did.
The next year the farmer hit a smaller stand, about 400 square feet with herbicide and turned it brown in about three days. I went to the big stand and cut the stalks to the ground and then applied Round-Up to the stems. I also found some plants that crossed the road. I treated these as well. Further, I over-turned my jon-boat and spread a tarp over part of the patch to try to kill it by shading it.
Japanese Knotweed
This last year most of the plants came back. This is a very hard to kill root mass. However, most of the outlying plants, as well as those next to the pond, did not come back. After moving the tarp and jon-boat, the plants sprang up. This last June, the farmer’s brother cut every stem on the small patch while I cut most stems on the large patch and sprayed herbicide on the rest. When I returned in late August, the plants in the small patch regrew to about three feet tall, or half their normal height. Same with the cut plants in the big patch, but those that may have not gotten enough herbicide were standing tall at six feet. I did notice though the stems were not as numerous. I resprayed both patches. By the end of September every plant in the small patch was dead, but the large patch had green growth. I sprayed again.
I look forward to early summer to see if we are making any progress on slowing or stopping the spread of the Knotweed. I doubt we will eradicate it, but we need to halt its spread into the field and especially into the pond area.