To really get to the root of the problem, and stop perennial weeds coming back, you need to kill the unseen roots too, and not just burn off the leaves. Glyphosate is the proven chemical of choice for broad spectrum weed control.
This larger 3L pack contains a lance sprayer application system, for easier application to larger areas, or for spot treatment. Once applied the glyphosate is slowly absorbed by the weed, and moves systemically through the plant down to the roots, as the weed feeds and grows.
It works best when it is warm and dry (apply when no rain is forecast for 24 hours), and when the weeds are growing fastest. You will not see much for a few days, but after a week, the tell-tale yellowing off occurs, and within 2 weeks a complete kill. Fantastic for controlling annual and perennial grass weeds, bittercress, buttercups, nettles, and any small seedling weeds smaller than 5cm across.
The weed control essential for your garden armoury!