Japanese knotweed ∗ This is how you get rid of the growing herb

Which location is suitable?

Japanese is growing in his homeland Knotweed often on volcanic ash fields. In Europe, the habitat extends over areas with moist soil, such as along bodies of water and wood-free riparian zones. But also on ruderal areas, at the roadside, along from Embankments and forests the plant settles. The Japanese knotweed is flexible in relation to the light conditions and grows excessively in both sunny and shady locations. The perennial is also stable, so that wind-exposed locations do not detract from its will to spread.

What soil does the plant need?

The resolute growth developed Japanese knotweed in almost any type of soil. The perennial thrives mainly in nutrient-rich, moist soil; Nevertheless, it has no inhibitions to settle in dry, sandy-loamy substrate as well. Only in acidic bog soil and permanent waterlogging you will hardly find Japanese knotweed.

When is the flowering time?

One of the unmistakable characteristics of a Japanese knotweed is the pure white flower. In the period from August to October, the panicle-like inflorescences rise above the leathery, broad, egg-shaped leaves.

Japanese knoeterich in a pot

Cultivation in a pot still harbors the slightest risk of falling victim to the vehement urge to spread of a Kamchatka knotweed. If you want to dare to experiment, the bucket should have a volume of at least 30 liters. Any commercially available substrate is available as a substrate Potting soil suitable on a compost basis. Before planting, spread a drainage made of gravel or potsherds over the water drain, because the plant cannot tolerate waterlogging in the long term. The maintenance program is limited to the following measures:

• Water regularly when the substrate surface dries up
• Fertilize is not required when repotting in fresh substrate every year
• Radical pruning in autumn or late winter

Since Japanese knotweed sprouts even the smallest parts of plants, the clippings should not be disposed of on the compost. Immediately after pruning is the best time to repot the vigorous plant into a larger container.

Is Japanese Knoeterich Poisonous?

As an invasive neophyte, Japanese knotweed threatens ecosystems around the world. Regardless of this, the plant does not pose a toxic hazard to humans or animals. On the contrary, the young sprouts can be prepared like rhubarb or asparagus. In the Japanese art of healing, the root provides a tincture that has a beneficial effect on blood pressure and is said to lower high cholesterol levels.
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What are the characteristics of Japanese knotweed?

During the flowering period from August to October, Japanese knotweed can be recognized by its white panicle flowers, which are quite pretty to look at. Outside of the flowering period, it is the leaves and shoots that serve as identifying features:

• Leathery green leaves 12 to 18 cm long
• Egg-shaped, pointed and 8 to 13 cm wide
• Arranged alternately on hollow shoots up to 300 cm long
• Knotweed shoots often appear overgrown with red

On the leaf veins on the underside of the foliage there are tiny hairs that are covered with bare eye are barely visible. If you run your finger over it, you can at least feel the hair. After the first frosty night, the above-ground parts of the plant die off within a short time. The huge rhizomes in the ground, on the other hand, survive the winter unscathed and sprout again with vehemence at the beginning of the following vegetation period.

How does the mechanical fight succeed?

If you have discovered a Japanese knotweed in the garden, you need to act immediately. In the early stages, the following mechanical control methods give you a good chance of success in preventing an invasion:

Spreading area 1 to 4 square meters
Once the rhizomes of the Japanese knotweed have only conquered a small area, you will come to terms with the invaders with consistent digging and pulling out. Be careful not to leave any pieces of root in the ground if possible. Go with that so often spade or the Pickaxe to work until no more shoots can be seen.

Spreading area 4 to 20 square meters
If the knotweed already colonizes a larger area, you will not reach your goal with excavation. Now the plant should be mowed close to the ground every 2-3 weeks from April to October / November. Then clean the equipment thoroughly so that no parts of the plant are carried over to other regions of the garden. Experience has shown that this control method requires up to 5 years of patience.

In order to properly dispose of the excavated or mowed plant parts, smaller amounts end up in the household waste. A larger quantity of rhizomes, shoots and leaves is in good hands in the municipal composting facility or is transported to the bio-power plant for incineration. Kamchatka knotweed has no place on the domestic compost.

How does the fight with black foil work?

With the help of a sturdy, black film, cut Japanese knotweed from the sunlight. Since photosynthesis comes to a standstill in the first place, the perennial dies over time. Of course, it takes a long line of patience of 1 to 2 years to triumph over the invaders. How to do it right:

• Cover the entire infested area with thick, opaque film
• Lay the edges at least 150 cm beyond the visible edge
• Spread out pieces of foil overlapping by 10-20 cm and fix them in the ground

In this way you achieve at least a considerable weakening of the population, so that afterwards digging up all the remaining rhizomes promises the best chances of success.

Are there any effective herbicides against Japanese knotweed?

The application of chemical Herbicides is increasingly viewed critically in private ornamental and kitchen gardens. The negative consequences for the surrounding flora and fauna are too great. Hobby gardeners only resort to this remedy when all mechanical methods of combating the Japanese knotweed fail. Broad-spectrum herbicides, such as Roundup or glyphosate, are not criticized for nothing: They are under suspicion Insect deaths contribute and various human diseases are due to application of broad spectrum herbicides returned. The herbicide affects our intestinal health and can lead to infertility. Skin diseases and cancer are also associated with it. Do yourself and the environment a favor and refrain from using such harmful substances.

How do I prevent invasive Japanese knotweed?

An effective prevention against Japanese knotweed is not to plant the perennial in the garden in the first place. The multi-faceted plant family of the knotweed family offers a wide range of beautiful species and varieties that adorn the garden without completely subjugating it. The distinctive candle knotweed is one of them, as is the majestic bush knotweed.

Create your garden on a new plot of land, do not use one Excavationthat could be contaminated with pieces of rhizome from a Japanese knotweed.

Is Japanese Knotweed Edible?

If you struggle with Japanese knotweed in the garden, you should still not turn a blind eye to its advantages. Knotweed leaves and roots are edible. The young shoots can be prepared for refreshing salads and make aromatic side dishes for meat or fish. When cooked, the leaves turn into a vegetable that is reminiscent of spinach.

Don't dig up the roots just to destroy Kamchatka knotweed. Peeled and boiled in salted water, they taste like asparagus. But be careful when disposing of uncooked plant residues, because they do not belong on the compost. The plant will sprout again from a 1 cm small piece of rhizome.