Muscadine grape vines aren't as cold-hardy as American fox grapes, but tolerate significantly hotter and more humid summer weather than the American fox and the arid-and-hot-summer-loving European grapes. Muscadine grapes also naturally possess excellent disease resistance to common pathogens that wreak havoc on European grapes. In the Deep South of the U.S., fruit growers favor muscadine vineyards for their ease of culture compared to other grape types. Often, Southerners call muscadines "scuppernongs."
The muscadine grape (Vitis rotundifolia) quickly climbs on or over trees and fences with vining canes 30 to 100 feet long. Just like its cousins, the European (V. vinifera) and American fox (V. labrusca) grape plants, muscadines produce edible fruits. Muscadine fruit clusters are smaller than those of other grape plants, with fewer but larger individual grapes. Muscadine grapes grow naturally across the Southeast, from Virginia and Tennessee southward to Florida, and west to Texas and northeastern Mexico.
Muscadine grapevines produce large, round to triangular, dark-green leaves with toothed edges and lighter green undersides. Tendrils exist to clasp and wrap around trees or branches for support; the tendrils are simple, not forked like those on European and American fox grapes. The grapes on muscadines ripen, then drop off the plant. They don't persist in a long cluster as on the other two grape species. Thick skins protect the muscadine fruits, which taste sweet but musky. Muscadine grapes are picked individually, not in large grape clusters.
Wild muscadine plants are dioecious--either male or female based on the sex organs present in the flowers. Through selection and breeding by horticulturists, numerous muscadine cultivars exist today. Many are self-fertilizing, producing male and female blossoms on the same plant, while a few remain single-sexed and require the nearby planting of a companion to ensure pollination and fruit set; for example, the cultivars Fry, Higgins and Jumbo are all-female plants. Black-fruited muscadine varieties include Cowart, Hunt, Noble, Jumbo, Nesbitt and Southland. Bronze-green fruits develop on cultivars Carlos, Higgins, Fry, Dixieland and Summit.
Muscadine grapes need partial to full sun in any acidic to neutral-pH soil that's moist but well-drained. Because they're so vigorous, plants in a vineyard are planted 20 feet apart on trellises. They're spur-pruned in late winter. Grow them only in U.S. Department of Agriculture plant hardiness zones 6b through 10a. Vines suffer damage once temperatures drop to less than 10 degrees Fahrenheit, and are killed at 0 degrees and lower. They also need 500 to 1,000 chilling hours--temperatures of 32 to 45 degrees--to flower in spring.
The Most Hardy Muscadines to Grow
Muscadines are a variety of plants that produce an edible berry often cultivated for wine-making. Muscadines are native to the southeastern U.S....