Muscadine grapes (Vitis rotundifolia) are native to the Carolinas, making them a relatively low-maintenance fruit that is well adapted to our warm and humid climate. Gardeners experience very few problems with this small fruit. However, one of the problems I hear about from time to time is low fruit yield. This problem can be attributed to many different reasons such as sunlight, poor pollination, nutrition, or lack of proper pruning. Proper pruning should be done on an annual basis to keep the plants at a manageable size and to allow the plant to use its energy for fruit production versus shoot and leaf production. Muscadines should be pruned when they are dormant, so now is the perfect time. Keep in mind that the vines will drip sap or “bleed” if pruned too late but this does not harm the plant.
Once gardeners know that they need to prune the vines their next question is how. To understand how to prune a muscadine vine you first need to understand its basic structure. A well-trained muscadine plant consists of a single trunk and 2 to 4 trellised arms or cordons and smaller fruiting stems called spurs. If the vines have been neglected for more than a year start by working in small sections to prevent being overwhelmed. Annual upkeep makes the pruning process much simpler. Start by removing any competing stems, suckers, or water sprouts that are growing from the trunk. Muscadines typically flower on new growth that emerges from last year’s growth; older stems tend to produce little to no fruit. If the vines have been neglected, the younger canes can be identified by their lighter brown color with numerous brown buds present. Ideally spurs should be spaced 6 to 8 inches apart across the cordons. Remove all older woody stems from the cordons and then prune back the stems from last year leaving three to four nodes or buds, which will produce fruit in the coming season. Regardless of whether you are tending to neglected vines or performing annual upkeep it will seem like an excessive amount of plant material is being removed. For more information see, HGIC 1403, Muscadine Grape.