I had a huge ivy patch the size of my family room in my back yard. It was bugging me, so I sprayed it with weed killer and waited a month. It all died and looked approachable. (You would think dead things can do no harm). Well I was wrong. I did clear the whole patch, but the price I am paying now is beyond description. Lesson learned - just because it's dead doesn't mean it won't make you itch!!