Question
I have heard these plants try to take over other plants in the same area or vicinity of themselves.  Is this true?

Answer
Hi Annette, they are aggressive growers,,and if you mean that they tend to envelope other plant in their immediate area, then the answer is most assuredly "yes", but if you mean that they somehow invade and actually replace them, then no. Keep them pruned back consistently and kept within their own bounds and they are wonderful plants. Nick