My 6 foot high hedges have a vine that wraps itself around one branch until it gets to the top (sunlight) where it branches out and pulls the tops together. It grows faster than the hedges so you can see them sticking out on top. They eventually develope flowers that look like white morning glories. How can I eliminate them? I have been searching and trying to pull them out at the roots for years. On occasion I have carefully dug out the root only to find that it continues underground. I have photos if I can figure out how to post them.