Friday September 23, 2016
Pruning is an annual event in our vineyard that helps control the size and shape of the grapevines. It also helps optimize the vines’ production potential, so we have beautiful and quality fruit yields.
Performed very carefully and entirely by hand with secateurs and loppers, this is an essential activity of vineyard management that sets the stage for the vineyard’s performance and productivity for the coming year and years ahead.
With 184 acres planted to vines at Mt. Beautiful, and over 20 unique blocks, pruning is an especially active time in our vineyard that spans the course of 2-3 months; typically June through August, during New Zealand’s winter months. It also happens to be the most expensive single activity of the year where our permanent staff joins forces with several seasonal hires in the vineyard.
Fin Grieve, our Vineyard Manager, uses his vast experience and judgement when choosing which of the two primary pruning methods (spur or cane) will be optimal for a given vineyard block, taking into consideration desired crop levels, the characteristics of each varietal and the block’s location.
Primarily we cane prune most of the vineyard however Riesling responds particularly well to spur pruning. In addition we also spur prune small areas of our Pinot Noir.
Here’s more information on these two different types of pruning techniques used at Mt. Beautiful / Teece Family Vineyard.
This method is normally better suited for colder climates or vines growing outside regions that are on the cold end of their preferred range, however, cane pruning is more labor intensive and risky, as it necessitates someone with a trained eye who knows how to choose the best canes. If a poor choice is made, the vine may produce less than favorable results.
With cane pruning, two or three canes growing from the head of the vine are selected and preserved for the following year. These canes should be a minimum of 8-10 mm wide (pencil width) and be one-year-old wood with evenly spaced and healthy looking buds (internodes).
The selected canes are then wrapped and tied to the trellis wire. Before removing all of the remaining dormant canes, replacement spurs are identified and cut back to two or three buds. These provide insurance that there will be at least some replacement canes should the vine not produce canes in the areas that we want for the following year’s pruning.
Spur pruning is easier for beginning pruners to learn, especially when pruning older vines that have pronounced cordons and spurs.
Cordons are canes that are not replaced (left on the wire for many years) and spurs are where the buds that produce shoots in spring are cut back to the cordon . With this method, the one-year-old wood growing from the spurs of the cordon are pruned back so only one or two buds are left as close as possible to the cordon. As the shoots grow they will need to later be tied to the trellis.
The advantage of spur pruning is that it generally yields a higher likeliness for a uniform bud break and also creates a spatial balance along the cordon which is advantageous for crop loading and minimizing disease pressure.
A disadvantage of spur pruning is that it’s possible for spurs to stop producing one-year-old wood, leaving permanent gaps in the cordon, If that occurs we usually replace the cordon with a new cane.