I have a few thoughts... I've tried cane pruning on a couple vines, and I couldn't tell any difference in the fruit quality or the yield so I abandoned the idea. I find spur pruning to be quicker and a lot simpler. In my opinion, either method is fine unless you are dealing with one of those few varieties that do no produce fruit on the first few buds. Dis-regarding those varieties, just go with what you know and what works for you. The only other reason I can see that cane pruning would be better is that buds with high light exposure usually produce more fruit. With cane pruning you can choose the canes that got the most light whereas with spur pruning your choices are very limited. We have plenty of sunshine here, so I don't see it as an issue, but in Oregon (not as much sunshine) it may be more important. I'm guessing the distinction between table and wine grapes is because, with wine grapes, you don't want high yield (many clusters are often dropped at veraison) so being a little less fruitful is no problem. I've visited several commercial vineyards here in Idaho. We have both table and wine grape vineyards in the area, and all that I have visited are spur pruning and producing very high quality fruit. I know that what is best for commercial growers is not always what is best for "backyard" growers, but in this case, it does show that spur pruning is commercially viable (at least in the Snake River Valley). Fruitnut, I think it was you who, a couple of years ago, advised me to visit the U of I research facility. I'm really glad you did, I got some vines (cuttings) from them and learned a lot about viticulture and fruit growing in general. Thanks for the suggestion.

I always wait until bud burst to prune my grapes. Since the buds at the ends of the canes tend to break first, I leave them unpruned until the danger of frost lessens, then prune the canes back to spurs which forces the basal buds to start breaking. This delays bud break by at least a week. The vines will bleed profusely, but it causes no harm.

Fruitnut is dead on... some varieties will grow 20+ feet in a single season while others not much at all. A healthy, established vine should be able to reach your 12+ foot arbor in a single season. What I would do is let them grow all bushy this year (don't prune and remove all clusters) to produce the best root structure possible. Then cut them back to 2 or 3 buds late next winter. They will explode with growth - select the strongest shoot and train it up your arbor (again removing the clusters so that it will be more vigorous). I think I'd put all the vines in the ground if possible as they will suffer some shock when you transplant from the pots. Are we talking total shade all day? Also 6 vines seems like a lot for an arbor. Established grape vines are quite vigorous and can grow quite large - it could turn into a mess if they are too close together. Athena - I think it is always a good idea to let them establish the first year. You'll get thicker trunks with longer nodes (short nodes are a pain as fruitnut pointed out). The general rule is you want shoots at least as thick as a pencil all the way to the height / length you will be keeping. If not, cut it back and start over.

From what I gather the multiple trunk training is primarily for the more tender varieties. To give them either ground heat with partial burial, snow cover, or just to allow for some dieback. I made a point of choosing very hardy varieties knowing they would be receiving full exposure. What sort of node spacing would indicate strong growth? How far back would you make a "hard cut". All the way back to the previous years growth? Or leaving several nodes on this years growth. Am I remembering correctly that any pruning would be done prior to bud swell? (this may be regional again)