Japanese Knotweed

Japanese Knotweed is a notorious herbaceous perennial that belongs to the buckwheat family, Polygonaceae. Its bushy appearance can is marked by hairless and hollow stems that are adorned by ovate leaves and white or greenish-white flowers.

The stigma of being the most invasive weed will always stay with Japanese knotweed. In Asian countries, it is highly valued for its medicinal benefits. Back in the 1870’s, Japanese knotweed came with a clean profile as an ornamental plant but now expensive and laborious methods are observed for its eradication.

Its aggressively invasive nature knows no bounds. Japanese knotweed has been witnessed to regenerate from barely 5 grams of root or stem. It can even grow through 2 inches of concrete too.

This dense shrub can attain a height of 10 feet at most. Its unattended growth can be a great threat to other plant species and the economic system. On the other hand, its redeemable medicinal perks have garnered the Japanese knotweed a great deal of respect.

Japanese knotweed roots contain emodin which helps regulate bowel movement and relieves obstinate constipation by acting as an excellent laxative. The roots also aid in promoting the vessels to function properly which ultimately leads to good health. Japanese knotweed plant is reported to cater to Lyme disease, respiratory diseases, skin disorders, and gingivitis.

Japanese Knotweed can thrive in almost any environment and weather conditions. According to the Wildlife and Countryside Act 1981, growing Japanese knotweed in the wild is considered an offense.

This exotically invasive weed grows at an extremely fast pace, surprisingly 2 inches per day, through its powerful rhizome network. This noxious weed emerges in early spring in acidic, seasonally wet soil, saline soil, and even fertile river edges due to vegetative spread.

Japanese knotweed lives a comfy life at the expense of its intelligent rhizome system. The shoots emerge in early springs which usually die in winters. Upon disturbing the ground, the rhizomes split into fragments. Each fragment is capable of producing shoots.

The ground can be disturbed by any means, including floods, earthquakes, or man-induced disturbances. The plant blooms during late summers till early fall. The floral scent invites bees and other pollinating insects to pollinate the plant and have their share of nectar.

After fertilization, the seeds develop which mature within two weeks and disperse through the wind to begin another lifecycle.

The Japanese knotweed young stalks and roots are harvested during spring.

The young shoots are harvested by anvil pruners whereas the roots can be broken easily by hand by pulling up the plant.

Japanese knotweed can be subjected to the freezer without any prior treatment. This way, the plant material can last for up to 6 months.

As much as the Japanese knotweed had garnered notorious attention, its medicinal advantages have compelled the herbalists to incorporate it in medicinal preparations.

• Tincture - Infuse freshly chopped Japanese knotweed in grain alcohol for 4 to 6 weeks. Strain the liquid and place it in a dark and dry place.
• Tea - Young Japanese knotweed shoots are allowed to sit in hot boiling water for 5 to 10 minutes to form the tea.
• Decoction - Fresh Japanese knotweed roots or young shoots can be incorporated into the boiling water at medium flame for 4 to 5 hours to formulate the decoction.
• Syrup - Japanese knotweed roots or young shoots can be simmered in a sugar solution to form the syrup.
• Infused oil - Dried Japanese knotweed is chopped and infused in olive oil for 2 to 3 weeks on a sunny windowsill to form the infused oil.