Is the site fairly sunny?
Grapevines are sun worshipers of the first order. The more sunlight the better. Therefore, vines MUST be planted in full sun whenever possible. Moreover, it has been said that great wine grapes are always grown as far north (in the northern hemisphere) as they can ripen. This maxim refers to the extra sunlight afforded by extreme latitudes. As a point of reference, consider that all of the great winegrowing regions of the world receive from 1200 to 1800 sunshine hours throughout the 6 principal months of vine activity (April – September in the northern hemisphere & October – March in the souther hemisphere).