Although spring in Ontario means warmer weather, more rain, and budding trees, it also signifies the resurgence of one of the province's most problematic plants, which, if left untreated, can quietly wreak havoc on your property.The highly invasive perennial, Japanese knotweed (Reynoutria japonica), has been dubbed the "world's worst plant" by some, thanks to its ability to develop massive underground root systems called rhizomes, which can damage foundations, crack pipes, break through concrete, and result in expensive repairs that could take years and thousands of dollars to complete.As a result, the International Union for Conservation of Nature (IUCN) has even added the species to its list of the 100 worst invasive plants in the past.The plant is native to eastern Asia, including Japan, Korea, China, and Taiwan, and was introduced to North America in the 1800s as an ornamental plant and to help control erosion. Today, the invasive plant is established ac...