I am not sure that a mulch around the foot vine will do much as vine roots travel for long distances in search of what they need but I suppose its worth a try. Even in the hottest parts of the grape growing areas of France I have yet to see a vine that has been mulched, of course practicality has a lot to do with that. One thing that has become popular in the area I live in is growing field beans between the vines over the winter. The whole lot is rotavated in the springtime to give a bit of extra nitrogen to the vines. I should say anything at all will do as a mulch if want to do it though... lawn clippings?
