By now, you've probably heard of Japanese Knotweed. It's a very invasive species of shrub, that's taken over in many areas of Highlands. I was asked recently about areas along Arnold Road, were is can be seen growing. There is a couple things about knotweed that you need to understand before you can attempt to control it. First, it is literally the weed from Hell. This plant, when sprayed with a non- selective herbicide at the wrong time of year, can actually make it stronger and healthier. Herbicide applications can only be made effectively in late September, early October, after the plant completes the flowering process. All plants are at their weakest state after flowering, because it takes a tremendous amount of energy and stored carbohydrates for a plant to produce a flower. Second, cutting it back only spreads it. It creates a dense plant structure and, oh...the plant material you hauled away or disposed of in the woods... those will all become new establish plants the following season. Cutting the shrub back is fine if you're going to fully burn the foliage that was cut off, on site. By reducing its height, it can be treated with an herbicide much easier. Third, Knotweed requires annual herbicide treatments for up to 5 consecutive years or more before it is eradicated. Finally, this is a plant that can grow through cement and asphalt. It is literally indestructible.
For the last 8 years, I've served with a local group focused on Knotweed eradication. We've mapped most areas of knotweed populations using the Town's GPS equipment. I've also worked annually to get funding from the Town of Highlands to treat these areas. While it helps, it sadly goes unchecked because more and more sites pop up due to the ignorance of residents. A lot of people don't know what it is and others simply don't care. I once had a resident tell me not to treat their right-of-way because they think it's a beautiful plant. In fact, they planted the Knotweed there years prior. Today, it's one of the worst infestations of Knotweed in all of Highlands and Cashiers.
Knotweed was introduced to the US in the late 1800's; specifically brought here to help with erosion control of soils. It definitely does that as well as destroys natural landscapes and ecosystems. This is one decision we all wish we could take back.