I have been receiving many phone calls requesting for treatments as the pesky/ irritating or down right scary plant has found itself enjoying the weather in lovely gardens. In general waiting a few more weeks for the leaves to develop into lovely healthy specimens will be all worth it as the plant will take the chemical a lot more readily.
At first glance this photo looks like a green background to a garden, looking closer the Japanese knotweed stems and leaves are growing speedily up to the sunlight.
I’m really excited – last year I was unable to find any suitable knotweed stems (i.e. ones that I knew for certain had not been chemically treated with). This year, however, thanks to two kind clients I have been able to make some really good jam.
The new shoots in this photo look so pretty as they quickly grow and lap up the amazing weather. However, look at the size of the dead cane from last year next to it? You can see why it quickly takes over a garden and why other plants don’t get a look in on the sunlight or nutrients from the soil.
You may have all been enjoying the amazing weather over the past few days. It can be quite frustrating when it starts to rain again.. In particular it can be frustrating when treating Japanese Knotweed.
The optimal time is with 6 hours before and afterwards rain free weather! This means that the chemical sprayed on the leaves has really good time to soak down into the root system!
Injecting the Japanese Knotweed stem is a good alternative, but the stems should be mature and often August-October is the best time for this method.
A nice little shoot popping up. I’m really pleased as this stem growing is so slender compared to the dead canes you can see in the background (last years growth). If left to grow it would probably be a lot slender than the previous year. (I will not be leaving it much longer to grow though!)
Also notice the leaves unfurling and the red shady lines to the leaves. That is often an indicator that the leaves have been affected by the last frost.