How big is your patch?

Ground elder is one of the most significant weeds on my plot. The areas where it seems to flourish are wet. I associate wetness with acidity so I have been using woodash on these areas? Too early to say whether my plan has worked or not, but if I don't keep on top of it, it soon forms a thick mat.

It is the "mat" underground that is a lot of the trouble as I can't plant anything near it as the roots just swamp over any new plantings.

I'm on clay - very wet in the winter.