The Japanese knotweed is a real monster: once planted, it ruthlessly crowds out any further planting and spreads unchecked. In addition, the "green monster" is very difficult to destroy.
Japanese knotweed likes to crowd out other plants
Why fight knotweed?
Although the Japanese knotweed is not poisonous to humans, there are numerous reasons for its destruction:
- crowds out native plants
- and thus also forage plants for insects
- and forage crops for wild animals
- breaks up asphalt
- and penetrates foundations.
Propagation via rhizomes
The roots of the Japanese knotweed can grow up to three meters - and even deeper - into the ground. They also have thickenings, so-called rhizomes, from which the plant grows again and again. In addition, the Japanese knotweed is also able to multiply via the smallest parts of the shoot - these root themselves and produce new plants.
What to look out for when eradicating Japanese knotweed
For this reason, it is essential to observe the following precautionary measures:
- Discard all plant parts, even the smallest, immediately.
- However, they do not belong in the compost or in the organic waste!
- It is best to dispose of it in the black bin
- or burn.
Garden soil with parts of plants or roots should also not be reused, but disposed of.
Control of Japanese knotweed
There are several ways to get rid of stubborn Japanese knotweed. However, chemical control with a broad-spectrum herbicide - Roundup is usually used - is out of the question in many cases. There are good reasons why these agents may generally not be used in private gardens without permission. In addition, particularly strict rules apply if you live in a water protection or nature reserve. Roundup and other herbicides harm the environment and contaminate water. The following methods have proven to be very tedious, but ultimately successful:
| method | execution | benefits | disadvantage |
|---|---|---|---|
| tear out | constant uprooting of young shoots with roots | Remove a few young plants | not possible with older plants |
| little sustainable / lengthy | |||
| dig up / dig up | Dig up the plants completely, including the roots | complete removal of a few young plants | must be repeated several times |
| Remaining root remnants drive out again and again | |||
| mowing | Mow off young shoots with the lawn mower every two weeks | strong restraint in growth | not complete elimination |
| Root remains remain on the lawnmower | |||
| grazing | Sheep and goats graze the overgrown area all year round | strong restraint in growth | not complete elimination |
| difficult disposal is eliminated | Animals have to be acclimated first | ||
| Cover with foil | Cover the plant with thick, black foil | plant dies | very tedious |
| Plant still needs to be dug up |
tips
If you don't know what to do with all the young shoots: Like our rhubarb, they can be eaten as a vegetable.