As some of you may well be aware, significant work has commenced improving access to fishing at Tir Canol in the Morriston, Swansea area on the River Tawe.
Old Knotweed has been cut and mulched prior to the new growth coming through. Thanks for the days of graft work done by Tiff Dew from the West Wales Rivers Trust, as well as for his help and equipment used in clearing windfall trees across the path with some club members.
We’ve also had assistance from Elen Evans of the North Wales Wildlife Trust’s Wales Resilient Ecological Network (WaREN) in tackling the invasive species, improving access along the way and getting stuck in with litter picking.
Because of the above, it is essential that nobody using this section of our fishing tries to pull up or cut any new growth knotweed where there is a treatment plan in progress. Doing so will prevent the treatment from working and let the hard work completed go to waste.
A vital role of cutting back the old growth is to create ideal conditions for the new growth to thrive. Whilst this may seem counterproductive, it’s essential that the new growth be allowed to grow to a suitable waist height or more, in order to allow the plant to absorb the chemical product used to treat it in the next phase of the treatment plan. Without this, the invasive knotweed will only impede Tawe fishing access.
Both Japanese knotweed (Reynoutria japonica) and Himalayan balsam (Impatiens glandulifera) are invasive species. They both have hollow stems, grow to a similar height and are found along river banks. But they have distinct characteristics. Japanese knotweed has small white flowers and heart-shaped leaves, and spreads through rhizomes. Himalayan Balsam has long, thin leaves and vibrant pink flowers. Himalayan balsam is an annual plant – it dies at the end of the growing season, unlike Knotweed that’s a perennial.
Whilst pulling Himalayan Balsam can be a successful strategy, pulling or cutting is counter productive for Japanese Knotweed. It prevents the treatment reaching the root. If you are not certain that what you’re looking at isn’t Japanese Knotweed, leave it alone!
See example above and North Wales Wildlife Trust Ecosystem Invaders page for more pictures and further information.
As well as the knotweed control measures undertaken and clearing of obstacles, some tree cutting was done to improve safety travelling along the path. Thanks to the use of the WWRT’s litter picking kit, we’ve also seen a double digit figure of sacks of litter removed from the area.
The result so far is a much improved area to enjoy some wellbeing time trout and salmon fishing in some nice pools on the River Tawe in Swansea. Whilst taking the occasional break near the river bank, a number of good fish could be seen jumping and thanks to the clear water conditions, swimming.