Last winter, I pruned the muscadines late and they leaked sap horribly for days afterwards. However, it didn't hurt the vines, and they produced a decent crop--at least a couple of them. This year, I have been a little more timely. I'm not done with them yet, but I have begun. I have just a couple of weeks to get my winter maintenance tasks done before things start to come out of dormancy.
Last summer the Ison grew a lot. It started off fairly well-contained, but stretched all the way to the end of the trellis line on one side. It also produced a lot of shoots near the bottom. Some side shoots off the top grew down all the way to the ground, then stretched out another two or three feet. All got pruned off this month, leaving about 3 buds on the laterals off the main horizontal vines (actually it's more like 2-4, some recommend 1-2 and others say 3-4; preserving forks where they occur).
In the background of this image, you can see another vine that hasn't been touched yet. Here's a closeup of the post-pruning appearance:
One thing I noticed is that the little tendrils it throws out to anchor itself sometimes latched onto another part of the same plant. Once they find something to lash onto, they get very tight. I cut some of them because they left deep grooves in the vine.
Eventually, the lateral vines will be big enough to resist that, maybe...but not now. Hopefully this leads to another good harvest this year.
