The Muscadine Grape (Vitis rotundifolia Michx.) grows naturally in the Southern and Southeastern United States. The grapes prefer sandy and sandy loam soil. The are a popular market crop, thanks to the ability of the vines to grow with low fertilizer input, as well as the native plant's natural pest and disease resistance. Muscadine grape vines produce purple or bronze colored fruit. The bronze colored grape varieties area called Scuppernongs. For optimal grape production, develop an annual Scuppernong pruning system.
Build a trellis for the Scuppernong grape vines made of sturdy and permanent material. Scuppernong grape vines remain productive more than 10 years. Gardeners often use upright posts of wood or metal with a wire strung across the top at a height of 5 to 6 feet. Or, a system with two wires is sometimes used with the lower wire located 2 1/2 feet high so weeds can be removed from around the vines. When planting Scuppernong grapes, space the vines 6 to 10 feet apart. The vines are pruned to encourage lateral cordons, or arms, that grow from the upright trunk of the grape vine along the wires. Grapes grow from these cordons.
Allow the Scupppernong grape vine to grow naturally after it is first planted. After the first six weeks of growth in spring, the vine will put out several branches from the main trunk. Choose the healthiest and most prevalent branch and trim all the other branches back to the main stem or to the ground, if necessary. Add a bamboo training stake or other lightweight stake tall enough to reach the lateral wires alongside the main vine stem or trunk of the grape vine.
Tie garden twine to the main vine or trunk of the Scuppernong grape vine to keep it attached to the training stake. The remaining branch or shoot will climb up the stake to the desired height where the lateral trellis wire is located. Do not wind the vine around the stake, because the stake is not permanent.
Prune off the top of the vine when it is just below the wire located at the desired height. You will see there are side shoots attempting to form along the upright vine. Pull or prune off all side shoots except the shoots located on each side of the vine near the wires. These will be trained to grow laterally along the wire. There should be available shoots within 6 inches of the wires. These shoots will be your lateral branches, or cordons.
Allow the lateral branches that remain along the upright vine to attach themselves to the wire and begin to grow laterally. It may be the second season before the lateral branches are completely developed. Once they are securely attached, remove the string and stake that was used to train the vine upright as it is no longer needed and can girdle, or damage, the vine as the vine trunk expands. Continue to remove all lateral shoots except the ones that form the arms, or cordons.
Allow the cordons to grow to desired length and develop side branches. However, every year, during the dormant season, the previous year's growth of each cordon must be pruned back to two or three buds. The buds, or spurs, can be spotted in early spring. Grapes will grow from the remaining buds.