Goutweed, or bishop’s weed, is one of the most tenacious invasive species. It will cover everything on the forest floor, including valuable native species. Its root system is so dense that it is impossible to completely remove it and it can come back from root fragments. This makes removing it manually a multi-year project. However, this plant has a weakness: because goutweed forms short, dense monocultures instead of growing among other plants, it can easily be smothered without affecting other plants. We decided to cover it with silage tarp because we had some lying around.
However, any tarp or black plastic should work just as well. We cut a piece of tarp, trampled the goutweed so that the tarp would lay flat, laid down the tarp, and covered the tarp with wood to keep it down. We have tried a similar strategy before, but we removed the tarp after less than a year, which was not enough to kill the goutweed. We are planning on keeping the tarp on for at least a year and then planting new plants in the plot. That way, the new plants will take the goutweed’s spot, preventing the goutweed from returning.
Stay tuned for updates on the experiment’s progress.