volunteer grape vine

hi!
i have a great, and prolific, volunteer mustang grape in my front yard.
it originates somewhere close to the house under oak trees, amongst asian jasmine. it grew unnoticed for several years until i decided to untangle the vine and stretch it out from under the trees and into the sun light. i propped it up and the side branches have filled in/out. so if you are standing in front of my house, there is a line of grapevine growing almost straight from the north to the south getting 6+ hours of full sun. last year i got about 3 bunches of grapes and this year there appear to be about 7. i know that to increase production, i need to prune it. however, everything i can find says to go to the main "trunk" and trim from that.
there isn't a vertical trunk- there's a vine that i propped up and encourage to grow.
suggestions? ideas?
thanks,
kris

Hi Kristen you don't say where you are and since I am replying from France my advice may be at the wrong time of year for you however I would not worry about not finding a trunk there are probably five or six just choose one and work from there . Good luck grapes are tough and difficult to kill

David

When I think main trunk, I think of a vine you can follow all the way back to the roots without obviously branching off another vine. However, I also agree with David. Choose one vine and treat it as a main trunk. Remember, grape vines are often propagated from cuttings. Any section of vine is willing to become a main trunk.

If you're really happy with this vine, you might even experiment with what you trim off. Propagating some of the productive wild grapevines is one item on my personal bucket list. With the speed this area is developing it's going to be hard to find wild grapes sometime soon.

I concur. I used to have a grape vine which was about 60 feet long. It ran along the top of a lilac hedge. Pruning consisted of leaving the main trunk (running atop the lilac) alone, and pruning the side shoots back to a few buds. So every 2 to 4 feet, there would be a little side branch that would grow new canes (and fruits) during the summer. It was very productive.

The only trouble I have with the that big is that they zoom up the nearest tree and I never get to see the fruit

David

cool!
i had been really worried about killing it, i'll be less worried now.
david, i think you're right about it being the wrong time of year to do anything right now- there are some grape bunches that are ripening as we speak.
in the fall, i'll do some agressive trimming and perhaps even try to root some cuttings.
thanks!