The only weeds that bother me, is dog fennel and I forget the name of the other one. It has the little yellow pumpkins on it with bean looking pods. Dog fennel makes a heck of a good screen, but I don't want it in the plot.
Sicklepod maybe. Stuff is bad news. Nothing eats it, and it can stay dormant in the seed bed for many many years,decades even; you till up a spot thinking it'll be the perfect plot,and next thing you know,it's covered up in sicklepod and it chokes out everything with nutritional value