Pink Geraniums

I agree but they fill a gap.

These and the red climbing rose provided the only bit of colour in my garden when I moved in eight years ago. At first I didn't know how thuggish they were and they soon spread everywhere. For the last two years I have been trying to rid the back garden of them. I think I am winning.
However, I have a very shady path to the east of the house and I am very happy that they have spread to the narrow border between the boundary fence and the path, where very little else will grow. :-)

THAT's where they are useful, Xela! I remove a clump occasionally if I need the space.