Unpruned muscadine grape vines often become an unproductive tangled mass. Yearly pruning is the key to maintaining healthy fruit-bearing wood. Now is the prime time for annual pruning of muscadines.
Fruit is produced on the current season shoots that grow from buds set on the previous year’s growth. One-year-old wood is the only source of fruitful shoots on the plant. Shoots arising from older wood are unfruitful.
The basic framework of a vine consists of the trunk, two or four permanent arms (cordons), and the fruiting spurs.
Muscadine pruning usually begins when vines become dormant in the fall, but late winter pruning in February or March exposes vines to less cold damage. It is important to remember that muscadines produce fruit on new shoots that develop from the buds of last year’s shoots.
Begin pruning by cutting back new wood that grew the previous year, leaving vigorous shoots with 2 to 5 buds. These short shoots or spurs will produce the new fruit-bearing shoots. This initial pruning can be quickly accomplished with a mechanical hedger or hand pruners.
The next step is to prune along the cordon to space the spurs about 4 to 6 inches apart. Remove downward growing spurs first. Cut the 1-year-old “fruiting spurs,” back to about 3 inches with 3 buds. As the vine grows older, it will develop clusters of spurs at each of these locations on the fruiting arm.
When the vine has been producing for three years (5- to 6-year-old vine), begin to gradually thin out the spur clusters. Prune by removing every third or fourth spur cluster to about 8 inches apart using lopping shears. This thinning will force new spur growth to replace these older spur clusters, allowing them to be gradually renewed over a period of years. It is critical to keep fruiting spurs (of 1-year-old wood) close to the original fruiting arm.
Each year, remove strong canes that have grown at the top of the trunk. This helps to maintain vigorous growth and good yields from the fruiting arms. If an arm becomes damaged by cold or broken, prune it back to the head of the vine and train a new cane to replace the damaged arm.
Finally, check your vines for tendrils that bind to the trunk or fruiting arms. Remove all tendrils attached to the trunk or fruiting arm of young vines to prevent girdling damage.
If your muscadines have gone unpruned, they often become a tangled mess of nonbearing wood. Those vines with only a thin layer of new growth over a mass can be cut back to the original cordon. This severe pruning of the entire plant back will drastically limit fruit production for the year.
An alternative would be to prune only one side back to the original cordon, and limit pruning the other side by leaving two to four buds of last summer’s growth. Then next winter, you can do the reverse by pruning the other side back to the cordon. You will have some grapes each year and still be able to clean up your vines by next winter.
On overgrown arbors, where you have seven or eight major branches, you can remove one or two large arms each year. Using the extended time, you can completely renovate the arbor.
Bleeding at pruning wounds may occur, but this has not been shown to harm the vine. Do not forget — an important part of pruning is to leave an adequate amount of last year’s wood on the vine.
Want more information on pruning muscadine grape vines? Join in a pruning workshop scheduled for March 6. Contact Lenoir County Cooperative Extension at 252-527-2191 for more details.
Peg Godwin is horticulture agent, Lenoir County Cooperative Extension Center. Reach her at Peg_Godwin@ncsu.edu or 252-527-2191.