In preparing the land we drilled a 10 inch hole 3 feet down into the grownd. This provides a great conduit for a tap root to grow so that the young vine gets roots deep into the ground where there is plenty of water. Drilling the hole also mixes the soil profile to at least 3 feet down. When we planted the vines in the hole we actually sank them quite deep into the ground so just a few inches of the trunk as well as the top buds on the vine were sticking out.
Its true while the other older established Foch and Millot vines in the vineyard were already leafed out, the new vines were just starting to show green leaf. So the vines have been slow to get going but they are starting to take off now.