I am clearing out the yellow loostrife. If I leave bits of roots in will I just spread it even further. I dont mind having some in the garden but I want to introduce a few different plants for next year.
It will spread and spread from any bit of root left in the ground. luckily, it's quite satisfying to pull up. Once you think that you have fot the lot out, more will come up to say hello next year. Just keep pulling and digging,
The best way to contain it that I have found is to buy some damp proof course plastic barrier. About 6 inches wide, thick , strong, black plastic strip from DIY shops. Make a wall of it sunk into the earth. It won't get over or under it.