We are on our annual hunt of this voracious plant. Before we moved I didn’t know what it was, I sure do now.
Once established, it tends to shade out native plants by producing a dense canopy of leaves early in the growing season and germination of our native plants is further compounded by the thick mulch of decaying canes and slow decomposing leaves left by the Knotweed in the winter. Although Japanese Knotweed is non toxic (edible even - it tastes like mild rhubarb apparently), it offers a poor environment for native insects, birds and animals.
Japanese Knotweed was first introduced to the UK as an ornamental plant by the Victorians. The problem is that it grows unbelievably quickly and it’s a highly invasive species. Currently Knotweed is listed on Schedule 9 of the Wildlife and Countryside Act 1981. This makes it an offense to either plant or cause (or encourage) the plant to grow in the wild. However, there is no obligation to report or remove it if it is growing on your land, but it really is wise to do so; if you see anything like the below appearing – kill it instantly-ish.
|Kill it - instantly-ish...|
One of the most effective methods of eradicating Japanese Knotweed is with the use of herbicides. For the best results apply just before the Knotweed's flowering, which generally occurs in late summer or early autumn. We use Glyphosate, we use it whenever we see a plant with enough leaves unfurled to make spraying viable we are so paranoid; also it can be very difficult to spray the plants when they are taller than you. This chemical penetrates the whole plant, including the root network.
We have been spraying since we moved here three and a half years ago and although it is obviously still with us the Knotweed has certainly been retreating and is nowhere near as prolific as it once was. Knotweed can lay dormant for 20 years so our vigil will have to remain in place for many more years to come.
There is a trial at the moment involving an insect that feeds on the sap of the Knotweed plant stunting its growth – but this may or may not work, and even if it does it could be ten years before it reaches us.
Doing nothing is not an option.
|As tall as I am - in just this growing season.|