I pruned a little early this year. I wanted to do it before the sap started running, like it did last year. I’ve been told that it doesn’t hurt the vines, but it’s still hard to watch the sap drip on the ground for several days.
This will be the third year of growth for these vines (third leaf). Since I only want to get about half a normal crop, I pruned to 1 bud instead of two. The hard decision to make was which canes to form spurs from. First, I noticed which canes grew from the bottom of the horizontal arm, or cordon. I wanted to form spurs that were upright, healthy, and spaced approximately 6″ apart.
The spurs each have one bud, that will each produce 2 or three shoots. In less vigorous varieties, each bud might produce only 1 shoot. Each shoot will produce 2 clusters, so I could potentially get 40 clusters (at .25lb each), or 10lbs per vine. That’s a fairly hefty yield for a 3yrd year vine, so I’ll have to be ready to drop clusters if necessary.
Here’s a couple of photos showing the end result. The last photo is the mass of canes I removed. Each vine had approximately 2 lbs of canes at the end of the season. I had pruned off maybe a third of this much during the summer, so maybe 3lbs total.
The number of clusters per vine is usually controlled by how many buds are left. If too many buds were allowed to grow, then clusters would have to be dropped later in the year.
According to the 20+20 formula for balanced pruning, I could leave 20 buds for the first lb of canes removed, plus 20 buds for each additional pound. That would say I could leave 60 buds on each vine, but that’s for 4 year old vines and older. A 3 year old vine can support half a normal crop load, but I’m only leaving 10 this year because I’m still learning and following the local wisdom. 4 year old vines are typically left with 2 bud spurs here, which would be 20 buds per vine. This is still low according to the formula, so I may let some extra clusters hang and see how it goes.
Due to our intense sun, not only will 2 shoots grow from each bud, but the buds at the base of the spurs will probably grow also, producing 1-2 shoots. My plan is to let the shoots grow as they may to provide a bit of extra shade, then drop clusters to keep the yield down to around 5 lbs per vine.