By Kat Yares, Garden Guides Contributor
Grapes belong to the Vitaceae family and are found growing all around the world. Grapes are divided into 2 subgenera: Euvitis and Muscadinia. The grape has been cultivated for thousands of years and, while there are some table grapes just for eating, most are used in wine making. Most grapes grow in clusters and the world grows approximately 144 billion pounds of grapes every year. Wine-quality grapes produce less per acre than do grapes intended for the table, jelly or raisins.
Grapes can adapt to many different types of soil, from high pH values to acidic and clay. Wine grapes should not be planted in highly fertile soils as this can hinder the production of the grape berry, which needs a more controlled environment.
* Climbing, woody vines characterize all grapes plants.
* Grape flowers are small, usually less than 1/8 of an inch.
* Grapes are berries.
Choosing a Variety
Grape vines should be chosen by the anticipated use of the grape. For an all-purpose grape, the muscadine or Concord grape grows well almost anywhere. Wine grapes should be chosen based on soil conditions and climate.
Grapes are grown from rootstock. Muscadine-type grapes are planted in trenches 20 feet apart, while other varieties are planted individually in rows 9 to 15 feet apart with 4 to 8 feet between plants. All grapes need to be trellised to achieve optimum fruit.
A trellis system can be made easily using a T-post fence post and heavy gauge wire. Grape plants should be pruned severely every winter by removing the shoots from the previous year. After pruning, the remaining plant is tied to the trellis wire. No special fertilizers are needed for grape growth. Grapes should be protected from animal predators such as deer.
Harvesting and Storage
All grapes are harvested based on ripeness and sugar content. Most table grapes are judged by the color and size of the individual berry. Muscadine grapes are picked individually as the grapes tend to ripen at uneven times. Raisins are allowed to dry on the vine before harvesting, so that the fruit reaches a sugar content between 22 and 23 Brix. Juice grapes are mature at 15 Brix, while the maturity of wine grapes depends upon the type of wine being made.
Grapes have a long storage live provided they are kept cold; some varieties of table grapes can be stored for up to 6 months in a refrigerator.