You want to keep grass and other plants/weeds from growing under the grapes. Weed and hoe gently under the vines to kill seedling weeds and deter other things from starting. The best mulch is your time. If the area at the base of the vines is clear, the soil will heat up and maintain higher soil temps to encourage growth. grass or other plants at the base cool the soil. As a result, growth in spring will be delayed. Keeping the soil clear of grass and weeds will produce the best results. So no mat, no stones, just busy hands under the vines.
You want to keep grass and other plants/weeds from growing under the grapes. Weed and hoe gently under the vines to kill seedling weeds and deter other things from starting. The best mulch is your time. If the area at the base of the vines is clear, the soil will heat up and maintain higher soil temps to encourage growth. grass or other plants at the base cool the soil. As a result, growth in spring will be delayed. Keeping the soil clear of grass and weeds will produce the best results. So no mat, no stones, just busy hands under the vines.