Those are some massive grape vines. I have never seen any that thick before. Too bad they don't hurt the box elder... I have heard that box elders have been outlawed in some cities, b/c they snap so easily and become extremely weedy. Do you do anything for the vines (fertilizer, soil amendment, etc.) or are they just that vigorous?

I give them fertilizer every 2 weeks in the summer and they tend to do fine. I get great tasting grapes from them and you can make wine if possible. I see boxelders everywere. Like small city cliffes, peoples yards, in cracks of concrete.etc.. They are a big problem in my area.