How Much Sun Do Grapevines Need?

Shade

• If the objective is merely for the grapevine to provide shade, it will require minimal amounts of sunlight. Filtered light through the trees, or partial shade, probably will be just fine. Care should be taken to prune off any clusters of grapes that begin to grow early in the season, however, as they will be unable to ripen and will sap the vine of valuable resources.

Table Grapes

• If the intention is to use the grapevines to grow table grapes, or grapes for personal consumption, a couple of hours of direct sunlight in the afternoon should be sufficient. The rapes will not win any awards and will not be the sweetest fruit you have ever tasted, but they will grow and some clusters will ripen. Purchase high quality fertilizer from a vineyard supply store to supplement the vine's lack of sunlight and maximize fruit production.

Wine Grapes

• If you are growing grapes to make wine, the aim should be to maximize the sugar content of the fruit. The maximum amount of sun exposure is required to produce quality fruit. At least seven hours of direct sunlight through the day is optimal, and the vines should be planted in north-south rows on the south side of a house to maximize sunlight exposure. Plant rows with sufficient room so that they do not overshadow each other, ideally leaving at least 3 feet between the rows.

Sun on the Fruit

• There are competing schools of thought as to whether sunlight falling on the grape clusters themselves aids the process of ripening. Regardless, properly pruned grapevines should have sunlight falling on the fruit simply because of their trellising system. The amount of sun reaching the fruit clusters themselves can be maximized by pruning the surrounding leaves away. This also aids in airflow and helps prevent mold and mildew, as well as other diseases and disorders of the vine.