Few plants are more maligned for their invasiveness than Japanese knotweed (Fallopia japonica). Rightly so, this plant is considered one of the worst invaders around the world. A member of the buckwheat family, Japanese knotweed is native to Eastern Asia in Japan, China and Korea. In its native habitat, it is quite adaptable. It can be found growing in a variety of locations but seems to be fond of edge habitat. It is one of the dominant pioneering colonizers on volcanic slopes and lava fields. This adaptability has caused ecological disaster elsewhere in the world. Introduced all over the world as an ornamental, Japanese knotweed is running wild in all manner of habitats. It is especially aggressive in riparian zones where it will quickly form a dense monoculture where nothing else will grow. It spreads by light weight seeds as well as underground rhizomes. These rhizomes can grow quite deep, making control very difficult. Japanese knotweed is so aggressive that it is not uncommon to see it poking up through pure asphalt or concrete. It is even known to break through the foundations of homes, a fact that has stirred up quite a lot of grief from home insurance lenders. Control of this pest is, as mentioned, quite difficult. The most effective way of getting rid of an infestation is to exhaust the root system. Regular cutting during the growing months helps. If the plants are sprayed towards the fall with an herbicide, they will translocate the chemicals down into their roots where the most damage needs to be done. There is some reports of success with biocontrols but those things take time. The upside is that the young shoots of Japanese knotweed are quite edible. Harvested young they can be cooked like asparagus or even baked into pies and such like rhubarb. The plant is high in the chemical resveratrol and is now replacing grapes for this use. The key to success in controlling this species is patience and persistence. Keep on top of it and you might stand a chance!
Photo Credit: Wikimedia Commons