Howdy. I've just this year become interested in growing grapes, bought a couple of plants, put up posts and wires for support for a four-arm system. I've read everything I could find on the web about pruning, and will be picking up a couple of good books on the topic before long, but in the meantime, I still don't quite understand something.

If I understand correctly, you choose a cane to train on the wire for fruiting, then dormant prune next late winter/early spring, leaving enough buds for a new fruiting cane and a couple of extra buds for renewal spurs. When they start to grow, you select one cane for fruiting, train it on the wire, and cut back the others, leaving one spur with a couple of buds for renewal.

Do you let those extra buds grow canes in the meantime? Do you allow them to grow and train them on the wires as well? And allow them to flower and set fruit? This wouldn't make sense because the "other" cane is called the fruiting cane.

If not, what do you do about the buds sprouting? Cut off the sprouts? Doesn't that interfere with saving those buds for the next year's fruiting canes? There's something I'm not getting here.

None of the descriptions say what those renewal spurs do with themselves while the "other" cane is doing its fruiting, if you know what I mean. They're just shown in drawings or photos just sitting there, little stubs with a couple of buds, but we know that's not what's going to happen, right? They're going to want to grow.

I'm still at the point where I'm training the vines up the the second wire this year, so I have some time to figure it out and do more studying, but this is bugging me. If anyone can clear this up for me, I'd really appreciate it.

TIA

Jo