Vitis rotundifolia Michx.
Common Names: Muscadine, Bullace, Scuppernong, Southern Fox Grape.
Related Species: Summer grape (Vitis aestivalis), California Grape (V. californica), American Grape, Fox Grape (V. labrusca), River Bank Grape (V. riparia), Sand Grape (V. rupestris), European Grape (V. vinifera).
Origin: The muscadine grape is native to the southeastern United States, found in the wild from Delaware to the Gulf of Mexico and westward to Missouri, Kansas, Oklahoma, and Texas. Many older varieties were selections from the wild, but the Georgia Agricultural Experiment Station and the U.S. Dept. of Agriculture have introduced a number of improved varieties that have become standard cultivars. The earliest named variety was Scuppernong, found growing wild in northeastern North Caroline in 1810 by Dr. Calvin Jones. Scuppernong has become another name for all muscadine grapes. Commercial production of muscadine grapes is essentially limited to the U.S. Southeast.
Adaptation: Muscadines are well adapted to the warm, humid conditions of the southeastern U.S., where the American and the European grape do not prosper. Its lack of frost hardiness also limits it to this same region, except for some West Coast locations. The plant may be injured by minimum winter temperatures of 0° F, and should not be grown in regions where temperatures frequently go below 10° F. Muscadines can be grown in California and adjacent areas, but are not as well adapted as other cultivated grapes. In coastal areas of the West the lack of sufficient summer heat produces berries that tend to be small and generally lacking in sugar. The vines also do not fare well in the low humidity of many interior sections. On the other hand muscadines perform satisfactorily in the warmer grape growing regions of California, Oregon and Washington.
Growth Habits: Muscadines are vigorous, deciduous vines growing 60-100 ft. in the wild. Botanically, they differ in significant ways from other grapes and are placed in a separate sub-genus, Muscadinia. In contrast to most other grapes, muscadines have a tight, non-shedding bark, warty shoots and unbranched tendrils.
Foliage: The slightly lobed, 2-1/2 to 5 inch leaves are rounded to broadly ovate with coarsely serrate edges and an acuminate point. Dark green above and green tinged yellow beneath, the leaves are glossy on both sides, becoming firm and subglabrous at maturity.
Flowers: Muscadines are dioecious, with male and female flowers on different plants. The small, greenish flowers are borne in short, dense panicles. It appears that both wind and insects play a role in the pollination of the female flowers. Breeding and selection have produced self-fertile varieties with near-perfect flowers, which also serve as a pollen sources for the female plants. For best results a perfect-flowered vine should be within 25 ft. of female vines, or every third vine when planted in a mixed single row. Muscadines do not readily hybridize with other grape species.
Fruit: The fruit is borne in small, loose clusters of 3-40 grapes, quite unlike the large, tight bunches characteristic of European and American grapes. The round, 1 to 1-1/2 inch fruits have a thick, tough skin and contain up to 5 hard, oblong seeds. In color the fruits range from greenish bronze through bronze, pinkish red, purple and almost black. Sugar content varies from about 16% to 25% for the sweetest cultivars. The wild fruits and some older cultivars have a musky quality similar to American grapes, although not as pronounced. Modern cultivars have a unique fruity flavor with very little muskiness. The flavor and appearance of the dark colored muscadine fruits are remarkably similar to the jaboticaba.
Location: As with all grapes, muscadines need full sun with good air drainage. If hardiness is questionable, they can be planted against a south-facing wall.
Soil: Muscadine grapes grow well on a wide range of soils but best results are obtained from well-drained sandy loams with a pH of 5.5 to 6.5. They will not tolerate low, wet ground. High pH can be corrected by adding sulfur and thoroughly working it into the soil. The vines are shallow rooted with most of their feeder roots in the top 12 in. of soil.
Irrigation: Regions with 30 inches of annual rainfall usually get enough rain to sustain the plants, unless summer dry spells stretch out past 60 days. In areas with less than that total, supplemental watering may be required. Drip irrigation is economical and satisfactory. In regions of dry summers, young vines may need watering during their first 2 or 4 growing seasons to help establish root systems.
Fertilizing: Nitrogenous fertilizers or complete fertilizers high in nitrogen are recommended. In the first year apply 1/2 lb. of 10-10-10 NPK after planting and then 1/8 lb. of ammonium nitrate in late May and again in early June. Spread the fertilizer in two parallel bands 12 to 14 inches from the trunk. Repeat in the second year, doubling the amounts and lengthening the bands to 48 inches. Thereafter, apply 2 to 4 pounds of the complete fertilizer each March and 1/2 pound of ammonium nitrate each June in a 6 foot long band beginning 1 foot from the tree.
Pruning: Annual pruning must be severe to keep new fruiting wood coming and to prevent vines from becoming tangled masses of unproductive wood. The basic framework of a vine consists of the trunk, permanent arms, and the fruiting spurs. Vines must be pruned each dormant season to maintain this framework. Current season shoots bear the fruit, but to be productive, these shoots must arise from buds set on last season’s growth, since shoots from older wood are generally sterile. It is important to leave the correct amount of fruiting wood.
Pruning is basically the same for all trellis systems. Only the arrangement of the fruiting arm is different. Two systems of training are used, the upright or vertical and the overhead or horizontal system. In the upright system, a 3-wire trellis is used, the lower wire being 2 ft. from the ground and the others 2 ft. apart. On the trellis the arms may be horizontal along the wires or fan-shaped from a low trunk. With this system the cane is taken to the top wire and the first year or when vigorous enough, and then topped to make it branch. The resulting laterals are trained along the wire to make the arms.
The overhead trellis provides more bearing surface per vine. The vines form a complete canopy about 7 ft. from the ground. The vines are trained to a single trunk 7 ft. tall with the arms radiating from the top of the trunk like spokes of a wheel. A mature vine will have about 8 arms. During the dormant season each year, cut back all shoot growth of the past summer to fruiting spurs 4 to 5 in. long. Remove shoots entirely that are not needed for spurs of fruiting arms. On young vines leave spurs of one year fruiting wood about 6 in. apart. As the vines get older, they develop clusters of spurs, or spur systems. Generally, thinning of these spurs is necessary after the fourth or fifth fruiting year. This thinning will force new spur growth to replace older spurs.
Propagation: Muscadines are commonly propagated by layering, as cuttings root with difficulty. The layering may be done at any time, but is commonly done in midsummer. Canes of the current season’s growth are bent down and covered with earth, the tips being left uncovered. By fall the cane will be developed roots and is severed from the parent. Seedling plants can also be grafted to desirable cultivars. Bench grafting is the method commonly used. Muscadine rootstock is not suitable for American and European grapes because of compatibility problems.
Pests and Diseases: Muscadine grapes are much less bothered by diseases than American and European grapes. They are essentially immune to phylloxera, nematodes and Pierce’s disease. In its native region several fungal diseases afflict the plant, including bitter rot (Melanoconium fuligineum) and powdery mildew (Uncinula necator) which attack the fruit, angular leaf spot (Mycosphaerella angulata) which affects the leaves and and black rot (Guignardia bidwellii) which attacks leaves, flower clusters and fruit. In the West only mildew is likely to be a problem. Leaf hoppers, aphids and flea beetles are occasional insect pests. As with all grapes, birds can also be a problem.
Harvest: In most cultivars the grapes in a given cluster ripen at different times and must be individually picked. The fruit also tends to fall when ripe. This tendency to drop can be used to harvest the ripe berries by spreading a tarpaulin or such on the ground and giving the vine a hard shake. Muscadine grapes start ripening mid September to late October. A mature vine can yield 20 lbs. or more of fruit. The grapes keep well, particularly when lightly refrigerated
Muscadine grapes are pleasant enough to eat out of hand despite the seeds and somewhat tough skin of some culivars. They come into their best, however, in making distinctive jellies, jams and juices. The grapes also make an excellent dessert wine with a flavor reminiscent of muscat wines.
Commercial Potential: In its home range in season the grapes are a common roadside item, where jellies, fresh juice and even wine are also often sold. If sufficient production were available, there is no reason that muscadine grapes elsewhere should not have as much market appeal as Concord grapes. In the West, however, they are likely to remain a home grown fruit.
Several dozen different muscadine cultivars are currently available from various sources with additional ones continuing to be developed. Some of the better known and better quality varieties are described below.
Female (Pistillate) Varieties
- Black Beauty
- Large fruit, 1-1/4 inch in diameter, skin black. Quality very good. Sugar content 24.5%. Ripens mid to late-season. Vine very vigorous. Clusters large. One of the best black muscadines ever developed.
- Black Fry
- Large fruit, up to 1-1/4 inch in diameter, skin black. Quality excellent, comparable with Fry. Sugar content 20%. Ripens uniformly, early to midseason. Vine very productive, disease resistant. Clusters large.
- Large fruit, 1-1/4 inch in diameter, skin bronze. Consistently large size throughout vine. Excellent, melting quality. Sugar content 24%.
- Very large fruit, up to 1-3/8 inch in diameter, skin bronze. Quality very good before fully ripe. Sugar content 21%. Ripens midseason. Vine moderately vigorous. Production good. Susceptible to black rot. Clusters very large.
- Fruit very large, skin pink to reddish-bronze, moderately thick yet tender. Quality good when fully ripe. Sugar content 17%. Ripens mid to late-season. Vines moderately vigorous. Production heavy to over-productive. Clusters large, compact.
- Large fruit, largest of any muscadine cultivar so far introduced, skin black. Quality good. Sugar content 16%. Ripens midseason to late. The fruit ripens irregularly over several weeks, making it an excellent cultivar for home use. Vine productive, disease resistant. Clusters large.
- Medium to large fruit, skin bronze, medium to thin. Flesh sweet with excellent and distinctive flavor. Sugar content 17%. Quality excellent. Ripens early. Vines vigorous, production good. Clusters medium.
- Very large fruit, skin black. Excellent flavor. Sugar content 21%. Fruit ripens earliest of all varieties. Vines very vigorous, production good. Large clusters. One of the best of all dark fruited varieties for home use.
- Large fruit, skin bronze. Skin thinnest of any large-fruited cultivar. Quality very good. Sugar content 20%. Ripens midseason. Vine vigorous, very productive. Disease resistant. Clusters large.
- Large fruit, 1-1/4 inch in diameter, skin black. Excellent quality. Sugar content 23%. Very vigorous, very productive. Disease resistant. Large clusters.
- Sweet Jenny
- Very large fruit, up to 1-1/2 inch in diameter, skin bronze. Quality very good. Sugar content 24%. Ripens early to midseason. Vine vigorous, very productive. Disease resistant. Clusters large.
- Fruit small, 1/2 in. in diameter, skin bronze. Flavor pleasing, similar to Scuppernong. Sugar content 16 %. Vine vigorous, very productive. Hardy. Clusters intermediate. One of the best bronze muscadines for wine making.
- Fruit very large, skin black. One of the largest self-fertile cultivars. Quality very good. Sugar content 19%. Ripens medium early. Vine vigorous, productive. Disease resistance good. Clusters very large.
- Fruit large, skin bronze. One of the largest of self-fertile cultivars. Flavor excellent. Sugar content 22%. Ripens midseason. Similar to Fry in flavor, color and size. Vine vigorous, productive.
- Dixie Red
- Large fruit, skin light red. Similar to Cowart in size. Quality very good. Sugar content 18-19%. Ripens in midseason. Vine vigorous, high yielding. Clusters very large, containing 12 to 30 berries.
- Fry Seedless
- Medium-sized fruit similar in color to Redgate. Sugar content 20%. Vigorous vine. Needs to be pollinated by another self-fertile cultivar. Tolerant to disease. Erratic yields.
- Large fruit, skin white, smooth, attractive. Quality excellent. Sugar content 16%. Ripens in late midseason. Excellent for wine making. Vine vigorous, very productive. Clusters medium to large.
- Large fruit, up to 1-1/8 inch in diameter, skin black. Quality very good. Sugar content 20%. Ripens over a period of 4 or 5 weeks beginning in early September. Vine vigor medium, production very good. Clusters medium to large.
- Medium-sized fruit, skin black. Quality good. Sugar content 18%. Ripens early to midseason. Vine vigor medium, very productive. Disease resistance good, except for powdery mildew. Clusters large. Excellent for making a red table wine.
- Medium-sized fruit, skin light to dark red. Quality very good. Ripens late to midseason, does not shatter. Uniform ripening of clusters. Clusters very large, up to 40 berries per cluster.
- Medium-sized fruit, skin black. Quality good, high acid taste. Ripens early to midseason. Vine vigorous, production good. Clusters medium. Recommended for red wine, juice and jelly.
- Large fruit, skin yellow bronze. Quality good, similar to Scuppernong. Ripens late midseason. Vine moderately vigorous, productive. Disease resistance good. Clusters medium.
- Agricultural Research Service, Northeastern Region. Muscadine Grapes : a Fruit for the South. U.S. Dept. of Agriculture, Farmers’ bulletin no. 2157. 1973.
- Dearing, Charles. Muscadine Grapes. U.S. Dept. of Agriculture, Farmers’ bulletin no. 1785. 1947
- Dearing, Charles. New Muscadine Grapes. U. S. Dept. of Agriculture, Circular no. 769. 1948.
- Facciola, Stephen. Cornucopia: a Source Book of Edible Plants. Kampong Publications, 1990. pp. 393-395.
- Poling, E. Barclay. Muscadine Grapes in the Home Garden. North Carolina State University, North Caroline Cooperative Extension Service, Leaflet no. 8203. 1985.