LSU AgCenter's Weekly Message

Prune Muscadine Vines Each Winter

(I first want to correct something I wrote in last week’s article about gifts for gardeners. I commented that anvil-type hand pruners were preferable, as they were less likely to crush stems. It should have said “bypass,” not “anvil.” Anvil-type pruners are more likely to crush stems.)

The muscadine is one of our native fruit plants and well-suited to much of Louisiana. One well-maintained mature vine can produce 30 to 100 pounds of fruit yearly. People sometimes find pruning intimidating, but muscadine pruning can be pretty simple if you keep some basic principles in mind.

Muscadines fruit on shoots that come from the previous season’s growth. Therefore, it’s important to keep some of this. At the same time, we want to prune in a way that keeps the fruit-bearing shoots close to the permanent arms (“cordons”) of the vine.

To balance these needs, you can cut back the previous season’s growth to “spurs” with about 2 to 3 buds. When vines are young and spurs grow directly from the cordons, leave about 6 inches between spurs. Remove shoots with a diameter less than that of a pencil, since they’re generally less productive. Cut off growth that’s on and right at the top of the trunk, other than the cordons. To keep the vine from strangling parts of itself, remove tendrils that wrap around the cordons or trunk.

Even if muscadines are pruned each year, the wood from which the fruit-bearing shoots grow will get farther and farther from the cordons with each successive year. Spurs grow into spur clusters or “bearers,” which look kind of like deer antlers. Once a vine is five years old or so, you can remove some of the bearers to encourage new growth to arise closer to the cordon.

If you’ve been around healthy muscadine vines, you probably know that they produce a lot of growth each year. Rather than trying to cut all of it off by hand, you can start by removing the bulk of it with electric or gas-powered hedge trimmers.

In fact, some research with the highly productive wine and juice cultivar Carlos suggests that pruning with hedge trimmers results in total yields as great as those resulting from hand pruning, at least in the short term. In the long term, there is likely to be some benefit from removing excessively dense, dead, and diseased wood by hand and to removing tendrils that encircle cordons. For those with limited time and a lot of vines to prune, a possible compromise is to prune by hand every other year or every few years.

If vines have not been pruned every year and the fruiting wood is far from the permanent structure of the plant – whether the vine is on a trellis or an arbor – the vine can be renovated. You may also want to renovate if there are large, unproductive gaps along a cordon.

Renovating a muscadine vine involves cutting a cordon back to an approximately six-inch stub and, after growth resumes, selecting a shoot that grows from the stub to serve as the new permanent arm. During the summer, remove the excess new shoots coming from the stub so that they don’t compete with the one you’ve chosen as your new cordon. The new growth will not produce fruit in the first season, but renovation allows you to prepare your vine for future productivity.

Prune muscadines in the winter, while they’re dormant. I often advise people to prune other deciduous plants in the late January to early February period, shortly before they start growing again, and it’s fine to prune muscadines at that time. However, as people who have pruned muscadines are likely aware, muscadines often “bleed” sap when pruned close to the time growth resumes. This bleeding is widely understood to not be harmful to plants, but if you want to avoid bleeding, you can prune earlier during the dormant season.

Let me know if you have questions.

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Dr. Mary Helen Ferguson is an Extension Agent with the LSU AgCenter, with horticulture responsibilities in Washington and Tangipahoa Parishes. Contact Mary Helen at mhferguson@agcenter.lsu.edu or 985-277-1850 (Hammond) or 985-839-7855 (Franklinton).