Inspect the ends of the grapevine and find sections that have four or more bud nodes in the 12 inches from the end of the grapevines.
Cut the 12-inch-long piece of vine with a sharp knife once all leaves have fallen and the plant goes into the winter dormant stage. Cut the vine at an angle with smooth strokes to prevent damaging the plant cellular structure.
Prepare the propagation tray by filling it with a medium made from equal amounts of sterile peat moss, coarse sand and perlite. Moisten the medium with water and combine all ingredients with your hands.
Stick the angled cut end of the grapevine into root-promoting hormone powder and tap gently to remove any excess powder. Stick the vine 4 to 6 inches into the soil so a minimum of three bud nodes are under the soil.
Place the grapevines in a warm location with indirect sunlight and a temperature of 68 to 70 degrees F. Mist the soil with water to keep it moist while stimulating root production. Avoid applying too much water to prevent a soggy soil that stimulates stem rot.