they are really tough, but my violets don't root very deep at all and they return from seed (don't think? the original plant lives more than a year or two?) and so they don't seem to hurt my other plants.
They pull out easily, but again this depends on the soil, more clay like soils are harder to pull weeds out of
I have never seen a yellow violet. Violas, yes, but not the wild violets. I grow violas too, love them. Pansies smell divine, but don't come back so I don't plant them.
