Grafting is the delicate process of connecting two varieties to achieve a plant that produces the fruit and above ground growth of the one variety, for example Chardonnay, with the root system of the other. Grafting is done for one, or a combination of the following 3 reasons. First, the desired variety has a root system that is unable to tolerate the soil due to insects like Phyloxera and Nematodes, as well as tolerance to poorly drained soils, pH issues, and salinity. The Second reason is resistance to virus transmission from weeds to the grapevine by nematodes. And the Third reason is to control vine size, by using low, moderate, or high vigor rootstocks to maintain a vine size that it is appropriate for the planting density and training system being used.