Apply 4 to 6 inches of mulch around the grapevine plants, extending the mulch out 2 feet from the centers of the grapevines.
Pull the mulch away from the stems of the grapevines so it is not in direct contact with the plants. This will ensure proper air circulation around the grapevines and adequate sun exposure.
Check the mulch often to make sure you do not have rodents nesting in it. Evict the rodents by destroying any nests you find.
Replenish the mulch every spring so it stays at the same depth. Check again for rodents and make sure the mulch is not touching any of the grapevines.