It is that time of year again – time to prune the vineyard in anticipation of this year’s grape crop! We start in February and guess what?
It’s February, in fact, February is almost over and I haven’t shared with you yet that we have started!
Since purchasing our Pellenc 4560 multi-function machine which we affectionately call the grape harvester, we have used it for pre-pruning the vineyard also. Read more about Pre-Pruning the Vineyard.
Here is a vine after pre-pruning but before hand pruning.
And now, drum roll please – after pruning:
Once the pre-pruner cuts the vines to about 8 – 10 inches above the cordon wire, we go through and hand prune to leave only the buds we choose. It looks pretty drastic but in reality we are leaving behind 30-40 viable buds, which is plenty enough to yield a bountiful crop.
Below you can see the basal bud and the one bud spur – the vertical shoot with one bud left on it. Theoretically, each bud will generate a new cane which will carry at least two clusters of grapes. So those 30-40 buds will yield 60-80 clusters on just four feet worth of vine rows!
We have found our Montepulciano vines can easily fully ripen 8 – 9 tons of grapes per acre. So we try to adjust the viable buds to achieve that. The vines this year are very healthy and should be able to easily ripen this load.
Bud break, when the buds swell and burst open with fast growing foliage, is triggered by the warming of the roots. The roots begin by pumping sap up through the dormant wood to the tips of the vines. Pruning the vines at the onset of the sap flow shocks the vine and interrupts the whole process. This interruption can cause a delay of the full bud break for up to 10 days. That may not seem like very long, but with our late spring freezes, 10 days can mean the difference between having a good crop and no crop at all!
Of all our grape varieties, Montepulciano is the latest to break bud and therefore has the least need for bud break delay – so we prune it first. Petit Verdot conversely, is our earliest to break bud and most likely to get frozen off by a late freeze. Therefore it needs the pruning caused delay the most and is pruned last in our vineyard. The pruning of our Aglianico, Roussanne and Muscato Giallo fall in between respectively.
Our nine acres of Montepulciano are now completely pruned and we have already started on the nine acres of Aglianico.