Typically, I see muscadine trellises with one wire, two poles, and then poles, t-posts or stakes at the actual plant. I have seen the same on a grape trellis. But, usually I see more elaborate trellises on grapes. Mostly, they have two sets of wires for two sides of grapes, and they have y-shaped or y-shaped posts on the end.
How come? Do muscadines simply not grow the same as traditional grapes? There are exceptions to this, but not usually what I see.
I am absolutely no expert on muscadines. It is a bit of a story why the ones that I had started growing at my house ended up not being ones that I got a chance to grow (to shorten it, divorce got in the way), and so I am just now growing them again, but I think that part of what you are seeing is the difference between a casual grower and a professional grower. When I drive through North Georgia and see the boutique vineyards I know that there is a lot of time and money tied up in the creation of those trellises, whereas the back yard and side yard ones are at people’s homes. Those people aren’t trying to turn a profit, and don’t need to maximize productivity. They also likely haven’t done a ton of research on what is the best design. I do intend to use the same trellis design as are used at some commercial vineyards. You will need to scroll down a bit to get to the meat, but here’s a short discussion of it:
The differences are based on growth and production differences between the species. Bunch grapes generally are not as vigorous as muscadines and are much less tolerant of shading. Even a little shading of bunch grapes results in uneven ripening. Muscadines ripen unevenly on the cluster and generally are picked one at a time.
A bunch grape trellis is configured to maximize sunlight on the leaves. Individual growing shoots are often trained such that they are parallel with enough space between shoots to permit full sun exposure. Bunch grapes in general tend to grow out and up. Muscadines tend to grow out, then droop unless they find a support to climb.
I am NOT a fan of the single wire trellis often used with muscadines. Single wire trellis is often used commercially because commercial pruning machines can trim the vines. My trellis is two wires separated by about 4 feet so that two separate main canes can be trained down the trellis. Production with two wires is generally much more than with a single wire.
The wires on my trellis are 6 feet off the ground. This puts them at eye level for me to pick when they get ripe. I can mow under the trellis with my riding mower. The vines tend to get very dense by late summer which shades out anything growing under the vines.
I have two wires each with one cane. Each plant is trained with two canes. It basically doubles production in the same overall amount of space. Perhaps more important, it gives me a backup just in case something happens to one cane, the other still produces a crop while a new cane grows to replace the one that is damaged.
I have as many as 4 trunks on some of mine. If I lose a trunk to winter damage, I still have muscadines. On a vine with one trunk, it has to divide twice by the time it gets to the 2 wires in order to have 4 arms.