Im in the process of trying to kill mine. I used http://www.ebay.com/itm/251776342997...%3AMEBIDX%3AIT It is killing it but ive had to spray it a number of times. I don't know if it would have killed it the first time or not. It didn't appear to killing it all but I only let it go 3 days. Ive now sprayed it 4 times over a 2 week period and its about 3/4s dead and most of the remaining leaves have black spots on them so they will probably die soon. I know I sprayed round up on it many times and it didn't touch it.