Grapes (Vitis vinifera) can be a smart addition to the edible garden, but might be difficult to eliminate whenever your needs change. Wild grapevines can be invasive, too. Most types of grapevine grow in U.S. Department of Agriculture plant hardiness zones 5 through 9. Rock salt will kill grapevines and it’ll also kill everything else in the area. It can take a long time to flush salt in the ground.
Rock salt causes grapevines to dehydrate and die. The grapevine roots bring the salt to the plant, along with water. Once in the plant, the rock salt prevents photosynthesis and disrupts the grapevine’s capability to distribute water throughout the plant. Basically, the grapevine dies of dehydration.
Rock salt will kill all plants in the same manner. Water from rain or watering dissolves the salt and spreads it farther in the dirt. Any plants which come in contact with the rock salt will also be killed. It can take years for the rock salt to be diluted and flushed from the soil so plants can grow again. Unless you don’t ever want to develop anything in that region again, you’re better off with another method to kill the grapevine.
Reducing grapevines down could be an effective method of removal, even though it takes time. The grapevine should be cut at the root, only above ground level. Every vine coming out of the root must be cut to work. The severed vines will dry and become easier to eliminate from whatever they’ve attached to. The roots will try to send up new vines, which need to be cut down quickly. Once the grapevines are severed, the roots will not have a supply of energy in the photosynthesis and will eventually die.
Grapevines need sunlight and don’t do well in full shade. It is also likely to kill them by packing them, although this will take a few years to kill the grapevine. Covering an whole grapevine might not be functional, but combining shade with cutting grapevines can be effective. When the severed root tries to send up a new vine, the shade stops the newest vine from prospering and supplying the root with sufficient energy to develop. Severed roots could be shaded by mulch along with other plants or things like tarps or thick plastic.