Rootstocks, clones and rootlings The ideal vine: a combination of different elements It's all the Americans' fault! The phylloxera invasion which came from North America last century radically changed viticulture. It made it necessary to use only the rootstocks of American vines (the only ones which were parasite-resistant), onto which portions of the shoots of the European vinifera were grafted. The roots are called rootstocks. The shoot (or scion) with one or two buds is grafted onto it; this joins together with the rootstock and becomes the main plant. Although they all descend from a phylloxera-resistant American species there are different types of rootstock, each ideal for a given terrain, climate, productivity requirement, vine-training system and the vine to be grafted to it. In the same way the scions are also carefully chosen with a view to identifying the clones which offer the best production for that type of vineyard and the wine which is to be produced. Usually when a new vineyard is planted rootlings are planted (rootstock with the scion already grafted onto it).