Japanese knotweed in particular has now proven to be a real plague. Once imported as a fodder plant for local game, the neophyte is spreading mercilessly and is very difficult to contain or combat. The reason for this lies in the very deep-growing roots, which can grow up to three or more meters into the ground.
How can you combat knotweed effectively?
To successfully control knotweed, methods such as pulling, digging, mowing, grazing, covering with film or injecting with Roundup can be used. It is important to remove the roots generously and destroy them carefully.
Fighting knotweed
The creeping knotweed is a popular climbing plant and a good choice when large areas need to be greened. After all, it is not without reason that the plant, which grows up to nine meters per year, is nicknamed “architect's consolation”. Due to its strong growth and the fact that its roots extend several meters into the ground, knotweed is difficult to destroy. Basically there are only two options left:
- Destruction with a herbicide (“Roundup”)
- radical cutting back of any new shoots
- Digging up the soil including removing all roots.
In particular, the use of the highly toxic Roundup is not recommended in private gardens, especially if there is a kitchen garden nearby. Mechanical removal, however, takes a lot of work and time - on average it takes about five years until the monster is finally destroyed.
Care for proper preventative care of knotweed
However, the enormous growth of the knotweed can be curbed in advance, although this requires considerable effort. This includes the plant
- if possible, don’t plant out
- but to cultivate in a large container instead
- cut back radically on a regular basis
- and to direct the creeping shoots in the right direction.
Fighting Japanese knotweed
In contrast to creeping knotweed, Japanese knotweed should under no circumstances be planted in the garden - it grows enormously, spreads quickly, displaces all other plants and can only be destroyed with effort and years of work. In the following table we have put together the common methods for combating the neophyte.
| What? | How? | Pro | Contra |
|---|---|---|---|
| Rip away | pull out young shoots including roots | Removing a few young plants | not possible with older plants |
| Unearth | dig up young shoots including roots | Removing a few young plants | not possible with older plants |
| Mowing | Mow young shoots every two weeks | Growth is severely curbed | no complete removal |
| Grazing | Allowing sheep and goats to eat the population | difficult disposal no longer required | no complete removal |
| Cover with foil | Cover plants with thick black foil | Growth is severely curbed | no complete removal |
| Roundup | Injection with Roundup | complete destruction | Environment also polluted |
Tip
Whichever type of knotweed you want to remove, remove the roots generously if possible and destroy them carefully. The plants sprout again from even the smallest root parts.
