Getting Larger Berries in Your Grape Bunches

 

'Flame' table grape growing in Las Vegas.

How do those grape berries get so big in the grocery store? Yes, its true they sometimes use hormone sprays to increase their size but you can do it naturally. Whether you are growing wine grapes or table grapes, it is important to "thin" the fruit to get larger or more flavorful berries. In table grapes the result is larger berries. In most wine grapes, the berries will not necessarily get larger (berry size is ultimately regulated by genetics) but they will get more flavorful.

Here is how.

Fewer Bunches Make Larger Berries

"Balance the fruit load." It is important in wine grapes as well as table grapes. That is a common moniker but what does it mean? It means to reduce the total number of bunches growing in each vine. The minerals taken up by the roots are divided up into fewer bunches and consequently fewer berries. Figure one good sized bunch every 6 to 8 inches.

Reduce Bunch Size

This is done by "pinching" or removing the bottom of the bunch when very young. Sound familiar? You do the same thing to peaches, plums and apples. Then it is called "thinning". The concept is the same. Fewer "mouths to feed" results in larger fruit. The same is true in grape berries. If you reduce the number of bunches AND remove the bottom third of each bunch, the remaining individual berries get larger.

Pinching or removing the bottom third of the grape cluster results in fewer berries and the remaining berries can get larger.

Variety Determines Results

The ultimate berry size is governed by its genetics. The variety 'Italia' is a seeded white grape that grows well in the desert and can be used for fresh eating or making wine. It can get very large berries. While the variety 'Pinot Noir' doesn't seem to get a much larger berry size by thinning but the flavor is more flavorful!