Pruning Muscadine Grapes
Pruning grape vines is an essential chore if you wish to produce an abundant crop for many years. Vines left to grow unchecked will produce greater amounts of vegetative wood that eventually becomes weak and less productive. Pruning removes excess vegetation, bringing a balance to fruit and foliage growth, which results in better quality of fruit and more productivity.
Grapes typically grown in Eastern NC are muscadine varieties, either bronze-green in color, sometimes referred to as Scuppernong, or dark purple varieties known for their sweetness. These grapes have their own distinct flavor, thick skins, and seeds. Popular muscadine varieties include ‘Carlos’, ‘Nesbit’, and ‘Noble’. Other grape varieties are classified as bunch grapes and include native Fox grapes and wine grapes. Bunch grape varieties are typically grown in the Piedmont and Mountain regions, as Pierce’s disease prevalent in the East, can shorten the lifespan of bunch grapes. If you wish to try growing bunch grapes in Pamlico County, you may have limited success. Be conservative in your planting and follow recommended management practices found in the Extension publication “Bunch Grapes in the Home Garden.”
As for muscadines, pruning and management is a little easier than bunch grapes. The best growing site for grapes is sunny locations with good internal drainage. Wetness is the greatest limiting factor in Pamlico County. If your soil has standing water after a rain, then either choose another site or consider creating a raised planting site.
Training of grapes is important, and the standard trellis system recommended for home growers is the single wire trellis. With this system, plants are planted between two poles 20’ apart, with a single wire stretched between each pole. This allows for the formation of two permanent fruiting arms, called cordons, to grow outwardly towards your poles. These cordons are maintained throughout the life of the planting, and from here all the fruiting wood is formed. When buds from the cordons begin to grow, this new wood will produce the vegetative and fruiting wood for the new year. All fruit is born on 1-year old wood, so pruning is used to reduce the excessive 1-year old wood that grew the previous season, and leave enough wood to bear the new season crop.
Start your pruning efforts by identifying 1-year old wood, which is typically smooth and contains buds. These buds are what you are trying to remove, but also what will produce new growth and fruit. The closer this new growth occurs to the cordon, the more productive it will be. Cut back vigorous growth towards the cordon, leaving about 7-8 buds per shoot. This area that contains the transition of 1-year old growth to the permanent cordon is call a spur. By pruning back towards this same location every year, you can develop fruiting spurs with spacing about 4-6” apart. This will help to create a balanced number of buds along the length of the vine that will maximize production.
After several years of pruning, you will notice that the fruiting spurs will grow further and further from the cordon. By selectively removing a few of the spurs each year, old dormant buds on the cordon will grow, replacing these spurs, allowing fruiting wood to form closer to the cordon.