The grapevine is predisposed genetically to put all its strength into its offspring - the grapes - before tending to its own survival. If it carries too many grapes, they will all be relatively sweet and ripe enough to attract birds, who will then scatter the seeds to the four winds. But the vine stock itself may not have enough stored sugars to protect itself (the sugar acts as an antifreeze in winter) and thus to survive. One symptom of this problem is an insufficient lignification of the young shoots. If this is observed, some grapes should be removed and the remaining harvested early. Fewer grapes mean that the grapes will be sweeter, and the vine stock will be healthier and have more energy during the winter -- everybody wins!