IMO, a large part of these "new grasses, weeds" we are seeing are coming from wild bird seed that a lot of homeowners put out to feed the little bastards.I am only about 30 miles from you and I have never seen that "grass" before. But, in all fairness, due to the dry spring and wet summer, I am seeing weeds and other plants here that I have never seen before. Some of my fields are covered in stuff that has never gown in them before that I recall.
It is people who spread the undesirable plant seeds around, not the birds, so why do you call the birds little bastards?