A precious medicinal plant from Asia has repeatedly spread nightmares in countries like the Netherlands and the UK.
Japanese knotweed (scientific name: Reynoutria japonica) is a well-known plant in traditional Eastern medicine, highly favored by East Asian countries such as Japan, China, and Korea. This plant is commonly recognized for its medicinal properties in treating rheumatism, joint pain, boils, and skin irritations, among many other ailments.
The stem of Japanese knotweed resembles bamboo, growing between 3 to 4 meters tall, with a speckled pinkish bark containing a lot of water. This plant is incredibly vigorous, thriving in spring and struggling in the harsh winter. Although it is an economic plant in many regions, such as southern China, in European countries or the US, Japanese knotweed has become a true nightmare.
Invasive Plant Disaster
In the mid-19th century, Japanese knotweed was introduced from Japan to the Netherlands as a rare plant. Initially, it was contained, but then the plant grew uncontrollably, invading many countries and regions.
Particularly in the United Kingdom, Japanese knotweed has become a calamity. An elderly couple, Liz and Adrian Atkinson, who live in Belfast, Northern Ireland, had worked hard for many years to acquire their dream home.
The English couple fears the invasion of Japanese knotweed. (Photo: Belfast Telegraph).
However, shortly after moving in, they felt terror as Japanese knotweed began to sprout through the concrete floor and cracks in the tiles. Even with high doses of herbicide, they could not eradicate the plant.
As time passed, their home in Belfast became 40% infested with Japanese knotweed, and their property, initially valued at £300,000, plummeted to just £60,000 – £70,000, leaving the couple “crying without tears.”
Many areas resorted to using chemical herbicides, but this method is not only costly but also requires continuous spraying for many years to be effective. The cost to clear a small plot of land infested with Japanese knotweed can reach thousands of pounds. In the UK, by 2012, properties affected by Japanese knotweed had lost a total value of up to $25 billion.
Unstoppable Growth, Roots Up to 7 Meters Long
Today, Japanese knotweed can be seen everywhere in England, from inside homes to alongside railways, highways, and bridges. They grow to destroy the concrete and foundation of buildings.
Research findings indicate that this abnormal invasion stems from three main causes.
Japanese knotweed grows excessively fast and robustly. (Photo: Sohu).
- First, Japanese knotweed is a highly reproductive plant, propagating through seeds and rhizomes. The seeds are relatively small, often carried by the wind for dozens of meters. The roots can also grow extremely robustly, reaching up to 7 meters deep without any issues. Just a 10 cm piece of root can sprout into a new plant, making its growth frightening!
- Second, while Japanese knotweed is edible, it is largely avoided by insects and birds. This lack of natural predators has allowed it to proliferate uncontrollably, disrupting the ecological balance in many European countries.
- The third reason is that the UK is surrounded by the sea and influenced by an oceanic climate, with warm weather year-round, allowing Japanese knotweed to thrive abundantly.
Destroying roads and many structures in the UK. (Photo: Sohu).
So, how can we control this aggressive invasive species? Scientists have discovered a sap-sucking insect in Japan called Aphalara itadori, which can naturally eliminate Japanese knotweed, but this species is not yet present in Europe.
Europe is currently considering whether to introduce this insect for control, but of course, thorough research is necessary to prevent this sap-sucking insect from becoming a new invasive disaster.
Transforming Invasive Plants into Gourmet Dishes
In many parts of China, Japanese knotweed is harmless. Instead of being despised, it has become a “natural snack” for people. The tenderest stems are often chosen, peeled, and mixed with chili powder, salt, and vinegar to create a dish that is sweet and tangy with a crunchy texture.
In many southwestern regions of China, the tender stems of this plant are also stir-fried or used in soups, especially in Guizhou, where the sour Japanese knotweed soup is a local specialty that leaves a lasting impression.
In China, Japanese knotweed has been transformed into a beloved specialty. (Photo: Sohu).
The value of Japanese knotweed goes beyond its taste. In the “Compendium of Materia Medica,” it is recorded that Japanese knotweed has blood-activating, heat-clearing, detoxifying properties, and is used to treat coughs and asthma. In modern medicine, the resveratrol found in its rhizome is widely researched and developed for medicinal and functional food applications due to its antioxidant and anti-aging effects.
Japanese knotweed, considered a “disaster” abroad, has become an intriguing specialty in China. This reflects the unique ability of the Chinese to utilize natural resources and can be seen as a commendable approach to managing invasive plants.
