About Jumbo Muscadine
A native of the southeastern United States, the muscadine grapes (Vitis rotundifolia) is a thick-skinned, large grape species characterized by a spicy, sweet flavor and a long lifespan lasting up to a century. Jumbo is a muscadine cultivar notable for its huge dusky black grapes, which can grow to about the size of a golf ball and may be eaten fresh or made into wine.
Jumbo is a fast growing, vigorous cultivar that can reach lengths of up to 15 feet in just three years. Fruits have a sugar content of about 16 percent, which is on the lower end of the muscadine sugar spectrum. Large clusters of fruits ripen over a period of several weeks in mid- to late season, anywhere from August until October. Because Jumbo is a female cultivar, the plant requires a self-fertile muscadine plant in order to fruit. Self-fertile cultivars include Alachua, a medium sized variety with 18 percent sugar, and Florida Fry, a sweet variety that produces golden colored grapes that are 20 percent sugar.
Jumbo muscadines thrive in U.S. Department of Agriculture (USDA) 7 to 9, where they will produce their best fruits in full sunlight. Though the vine may survive shady areas, fruit production will be limited. Muscadines are tolerant of a range of soils, though a well-draining, moist soil with a pH between 5.8 and 6.5 is ideal. Planting on a slope may be helpful, as the vine will absolutely not tolerate standing water.
Muscadines are best harvested in the morning or evening, after the afternoon heat has passed. They may be picked in bunches or individually by hand, or the vine may be shaken over a tarp until the grapes drop. Avoid ripping the skin of the grapes during harvest, as this will shorten their shelf life. Muscadines can be refrigerated for up to three weeks at a temperature of 33 degrees F, though they will probably taste best during the first week.
When planted in the right conditions, Jumbo is a largely disease resistant cultivar, though some fungal diseases such as powdery mildew, leaf spot, and rot may occur. Following good cultural practices will help prevent many disease and pest problems. The University of Florida recommends keeping the area under the vine free of debris and weeds, as well as using a trellis or training structure that allows air to circulate freely. Good air circulation helps to dry foliage and prevent disease from settling in. Fungicide may be used to treat existing fungal diseases.
Michelle Wishhart is a writer based in Portland, Ore. She has been writing professionally since 2005, starting with her position as a staff arts writer for City on a Hill Press, an alternative weekly newspaper in Santa Cruz, Calif. An avid gardener, Wishhart worked as a Wholesale Nursery Grower at Encinal Nursery for two years. Wishhart holds a Bachelor of Arts in fine arts and English literature from the University of California, Santa Cruz.