The number of buds retained will be dependent on the vine's growth last season and its bud survival rate. The most vigorous vines will be pruned to keep 20 bud times the bud survival rate. The grapevine is an easy plant to propagate if it does not require a special rootstock. Non grafted varieties are grown from cutting of the mother plant. The cuttings should be about the size of a pencil in diameter or larger.
Larger cuttings are more difficult to work with, but they grow well.
It should be 3 to 6 buds long. The preferred size is a 4-bud cutting that is about 12 inches long. The cuttings are placed in the ground in early spring and allowed to sprout and grow. The cutting needs to be oriented in the same direction that it grew. Wine grapes that have American parentage can usually be grown on their own roots, called own rooted vines.