Japanese knotweed isn't your average Pennsylvania weed.

The weed can be seen all over our area, especially on river banks and along train tracks and roads. Local homeowners and municipalities find it hard to control the growth of the invasive weed as normal herbicides don't work effectively to kill this pesky weed. Its invasive root system and strong growth limit plant diversity and damage foundations, buildings, flood defenses, roads, paving, retaining walls and architectural sites. It can also reduce the capacity of channels in flood defences to carry water.Japanese knotweed and giant knotweed are herbaceous perennials that form large colonies of erect stems that can reach nine feet in height. The plant is native to Japan; giant knotweed comes from Sakhalin Island in northern Japan. They were introduced into North America for ornamental use in the late 1800s.Japanese knotweed is now widely naturalized in Europe and North America.In the east it extends from Newfoundland to North Carolina. It is also widespread in the Midwest and in coastal areas of the Pacific Northwest. It is most commonly found lining the banks of creeks and rivers where it often forms an impenetrable wall of stems; it also occurs in wetlands, waste ground, and along roads and railroads.They spread by vigorous rhizomes (horizontal stems that grow just below the soil surface). Japanese knotweed and giant knotweed are very similar in appearance and are known to hybridize. The weed can also be found in 39 of the 50 United States and is listed as an invasive weed in Pennsylvania, Ohio, Vermont, Virginia, New York, Alaska, Oregon and Washington. It is also listed by the World Conservation Union as one of the world's 100 worst invasive species. The roots of the Japanese knotweed are traditionally used in Chinese and Japanese herbal medicines as a natural laxative. The active principle responsible for the laxative effect is emodin, present in its natural form as a complex of its analogs.To eradicate the weed, the roots need to be killed. Picking the right herbicide is important, as it must travel through the plant and into the root system below. Glyphosate is the best active ingredient in herbicide for use on Japanese knotweed as it is 'systemic' and penetrates through the whole plant and travels to the roots. Digging up the rhizomes is a common solution where the land is to be developed, as this is quicker than the use of herbicides, but disposal of the plant material is difficult, governed by law in the UK, where it is classed as controlled waste.In Pennsylvania, knotweed was extensively planted at strip mine reclamation sites.Kevin Steigerwalt, Tamaqua borough manager, stated, "This weed is hard to kill with traditional herbicides." He added that it also takes longer to remove as it grows fast and covers everything.