Growing Grapes in Indiana
Grapes are the most widely grown commercial fruit crop in the world, and also one of the most popular fruit cropsfor home production. Though grapes are adapted to awide range of climates, the best production occurs in regions that meet certain specific climatic conditions. Successful production of grapes in Indiana depends on matching adapted cultivars (cultivated varieties) with good sites and following good cultural practices. Indiana’s climate is suitable for production of high-quality juice, wine, and table grapes and there are many cultivars with adequate winter hardiness to survive in all regions of the state. However, cold winters and hot, humid summers can make grape growing a challenge.
The grape is a woody perennial vine that can live for many years with proper care. Grape flowers and fruit are borne only on new shoots that arise from dormant buds formed on the previous season’s growth. As a shoot matures and drops its leaves, it is known as a “cane”. It is from canes that the next year’s fruiting wood is selected at pruning time.
Grape buds are classified as compound buds because they contain a primary bud and one to four separate, smaller buds. When growth starts in the spring, the primary, or central bud breaks dormancy and produces the fruiting shoot. Low mid-winter temperatures may cause death of primary buds, and spring frosts may occasionally kill the tender primary shoots during early stages of growth. If this happens one of the smaller buds usually develops into a shoot. These shoots are usually less vigorous and produce fewer, smaller fruit clusters. However, as these shoots grow, new compound buds are formed which will provide potential for a full crop the following season.
Flower clusters develop on shoots at nodes opposite a leaf. At nodes where fruit clusters are not formed, a tendril will develop. The number of clusters that develop per shoot is a genetically controlled characteristic of the cultivar that is not influenced much by the environment. The number of berries per cluster, however, is greatly influenced by the health and vigor of the vine, the environment during bloom, and other factors. Proper care of vines is necessary to meet full fruiting potential.