So I am not a very good gardener. Things don't die but I don't know how to weed and make gardens and stuff. The house I bought a couple years ago in Ontario has lots of "wild" landscaping done (nightmare for me as you can imagine). There's what appears to be an old garden (10 x 10 approx) at the back of the property that is overrun with weeds.

It's all one kind - a rather tall (2-3') plant with yellow/green palmate leaves and really deep, extensive root systems. Pulling the plants out by the roots is very difficult. I tried to pull them all out but I think MORE came back. I realize this would be easier with a photo but I only thought about asking this question at work! I planted some berry shrubs last year - they are growing well enough amid all the weeds.

So I guess I have a couple questions. Is it possible / realistic for a noob like me to remove these weeds permanently? I could transplant the berry shrubs and tarp it for a couple years.

BUT I was hoping to instead find some kind of flowering plant that's even though than these weeds. It can take over the whole garden area if it wants as long as it's prettier than whatever this plant is. Lots of flowers and minimum work from me (I can prune like a champ though so bushes / shrubs are welcome) would be ideal.

Thanks for your suggestions!