Roundup will not kill or control tree of heaven. If you go to the website: gardeningknowhow.com you can get a good explanation on how to control tree of heaven. When you get the website go to the top right at the magnifying glass that is the search box and type tips on stink tree control. As I said, this will give you a good explanation of how to control tree of heaven. It’s very hard to get control of how to get rid of tree of heaven. Thanks for the question.