Our plants have thick wood at the base; I don't know how old they are, but the trunks are about two inches across; maybe about five inches in diameter.
I tried pruning them yesterday, and discovered that the trucks go a LOOONNNNG way before sending out canes. Some of the trunks are bent and curled, often sending out canes as much as three feet from where the trunk comes out of the ground. All the info I have seen assumes a short trunk with canes coming out just a few inches above the ground, but on these plants you have to travel quite a bit to get to new growth. I suspect the plants were not trained well earlier, and the pruning took place farther and farther from the base each year.
My question is, is there any way to sort of train these back to getting growth closer to the base? It seems like there is a lot of wasted space now, as the trunks go several feet out of the ground before any growth. The trunks are heavy and lean on the wires. All websites I have looked at give instructions for pruning based on a plant that has been trained well to grow from the base. I can't seem to find any info on pruning grapes that have such long trunks.
Any information or web sites would be greatly appreciated. --Suzanne