I wonder if your side of the fence line, if this is "shared" with the Oleanders, is in need of a good dosing of Round-Up or ground sterilent. You know, to get rid of the stuff on your side that "you" don't want...if you know what I am talking about. I used to keep "my" side of things sprayed for weeds, can't help it if the plants roots don't know their side from the other....hmm? Opps.