Short permanent arms originating from the trunk are trained so the foliage will cover the arbor to the best advantage. For best results, arbor vines should receive annual renewal pruning. Unlike many other fruits, the sugar content does not increase after grapes are picked. Often grapes have good size and color one week before the sugar content is sufficiently high. After the sugar content has peaked, the quality of the grape deteriorates rapidly.
Yield depends on the cultivar, climate, and vigor of the vine.
In the third year, vines can be expected to produce 5 to 10 pounds of fruit. If you plan on storing grapes for later use, proper postharvest care is essential for keeping them in edible condition. Grapes in the best condition when picked will last longest. Handle clusters with care and remove any discolored, injured, or undesirable berries. Wrap grapes loosely in plastic material to prevent excessive loss of moisture.