Gerald L. Klingaman
Plant Common Name
About 60 species of woody, tendril-climbing vines make up the genus Vitis. These deciduous plants are native primarily to the temperate regions of the Northern Hemisphere. Long cultivated, grapes are economically important fruits for juice, wine, cooking, and the table. Some are also used as ornamental plants. By far the most commonly grown is Vitis vinifera, the European wine grape.
Long flexible climbing stems with grasping tendrils clamber up and over supports; a few Vitis are shrubbier in habit. The stems have shredding bark that peels in strips. The leaves alternate along the stem and are typically toothed and lobed. They often turn brilliant colors in fall.
Branching clusters of tiny, greenish, often fragrant flowers are borne opposite the leaves in late spring or summer. Wild plants of Vitis vinifera, and several other economically important grapes such as the fox grape (V. labrusca), typically bear only male or female flowers, thus requiring cross pollination to produce fruit. With a few exceptions (including most cultivars of the muscadine grape, V. rotundifolia), modern domesticated grapes have bisexual flowers and are self-fruitful. Fruit production may be enhanced by the presence of another variety and of insect pollinators. The fruit is a berry which ripens in late summer or early fall. Ripe fruits can be green, red, purple, bronze, or other colors. The fruits of wild grapes and wine grapes typically contain 2 to 4 pear-shaped seeds, but many seedless table grape varieties have been selected.
Several species, many hybrids, and hundreds of cultivated varieties of grapes are grown today. Each is best suited to particular conditions and uses. Vitis vinifera originated in western Asia and was first domesticated more than 6000 years ago. It is a vigorous woody vine that produces long dense bunches of flavorful tight-skinned fruit that is good for wine production or eating. Although less hardy than fox grape, it requires some winter chill, and prefers high heat in summer to set quality fruit. Native to the eastern United States, fox grape is primarily grown for eating, juice, and preserves. Its thick-skinned fruits have a musky, "foxy" odor when ripe. It has been hybridized with V. vinifera to produce the so-called French Hybrids, which are important wine and eating grapes in the Northeast United States and other areas with cold winters. Muscadine grapes are from the Southeast United States and thrive in hot humid summers. Although intolerant of severe cold, they require some winter chill to thrive. They bear their large, thick-skinned fruits in small loose clusters rather than the large tight bunches characteristic of most other grapes. Muscadines are used for home fruit production, roadside markets, and commercial wine and juice.
Grapes vary greatly in hardiness and cultural requirements. Choose plants based on their suitability to local conditions. Full sun, well drained soil, and a large strong supporting structure are generally required. For optimal production, most grape vines need regular care such as annual pruning, consistent pest control, and harvesting. Some types are grafted on rootstocks which impart pest resistance. In addition to being ideal candidates for the culinary garden, grape vines make lovely coverings for arbors, pergolas and walls.