Culmina News

Yield Planning & Pruning at Culmina

March 15th, 2016

Step 1: 2015 Growing Season Assessment & Vigour Analysis

Like any planning process, a solid roadmap for the future can only be put in place after you’ve evaluated where you’ve already been. Planning in the vineyard is no different. Preparing for the season ahead at Culmina always starts with an in-depth analysis of the previous growing season – more specifically, with Pascal spending a few cold winter weeks on the ATV. During the quiet cold months, Pascal drives down every other vineyard row to assess the vine health and vigour of each panel of vines in the vineyard. While passing through the dormant blocks, he assesses the vigour of the vineyard by attributing a value of 1 (low vigour) to 5 (high vigour) to each panel (or every five vines). He then uses this raw data to map out the vigour of the vineyard – both figuratively and literally. With this assessment map, he then creates a plan for the season ahead that includes decisions involving pruning, composting, irrigation, and the management of cover crops.

Block data collected by Pascal for his Vigour Analysis

This painstaking process serves as the baseline for creating a plan for the next season ahead: one that overall serves to reduce high vigour vine areas and increase the low vigour ones. Why? So that as much as possible, all of the vines in the vineyard develop and grow at the same rate, with the resultant fruit also ripening evenly at the time of harvest within each of the vineyard blocks.

Step 2: Creating a Pruning Plan

Once Pascal’s 2015 Vigour Analysis is complete, he then creates an individualized pruning plan for each of the vineyard blocks. The areas that are identified as weak are targeted for pruning to a smaller number of buds to allow the vine to regain strength in the upcoming season, while those identified with high vigour are targeted with different pruning objectives. Any short-term losses in yield are viewed as necessary for ensuring the long-term health of the vine.

For our mature plantings on Arise Bench, the plans generally involve spur-pruning. In this style of pruning, a cordon – or permanent cane – is established by tying down on the trellising wire. Shoots from the previous growing season are then cut to establish ‘spurs’, which at Culmina are typically 1 to 2 buds in length. During the upcoming growing season, each of these buds will erupt with growth, and will be responsible for 1-2 bunches. The advantage of spur-pruning is that it allows you to evenly place and distribute clusters along the cordon, allowing for more uniform ripening within the vine. This is especially important for the late ripening red varieties on Arise Bench.

Spur-pruned vines in Block I on Arise Bench

However, in other areas, Pascal specifies cane-pruning techniques. For instance, cane-pruning is used almost exclusively on young vines and in cooler areas like Margaret’s Bench. In this pruning method, two canes from the previous year are selected by the team and then tied down to the trellising wire, with this third emergency “kicker” cane left un-cut and still attached as back-up. Because new canes need to be identified and tied down each pruning year, this method is definitely more time consuming than spur pruning, but is deemed preferable in these areas due to the potential for bud damage if there is any late spring frost. If a frost event does take place, bud loss can potentially be protected against with the emergency cane, offering the vine a potentially undamaged cane to tie down.

Cane-pruning young vines in Block K on Arise Bench.

Cane pruning is also used on Margaret’s Bench due to the varieties that are planted there being very well-suited to the technique. White varieties like Grüner Veltliner, Riesling, and Chardonnay produce less ‘fruitful’ shoots on the first or second buds of each cane. Therefore, if spur-pruning were used in these blocks, the shoots developing out of the first spurs could potentially be less fruitful than the shoots out of the exterior spurs. This could potentially affect the evenness of yield (and ripening) on each vine.

Step 3: The Team Executes the Pruning Plan

Once the Pruning Plan is in place, Pascal hands it over to the Vineyard team to execute. Before a single cut is made, however, our Vineyard Technician and Assistant Winemaker, Jaime, spends significant time training the crew to ensure that the season’s objectives are understood and internalized. Jaime not only communicates the year’s objectives, he also works with the crew for as long as it takes for them to understand the principles involved.

Pruning in the distance, Sohan in Block B on Arise Bench.

What exactly does this involve? It involves each person understanding that when they prune in the vineyard, they need to examine the health and vigour of each individual wine, and make pruning adjustments as necessary. Pruning is therefore not simply a matter of unilaterally opting to leave x many buds per vine, but rather involves a determination of how many buds to be left on any given vine due to its current health and vigour. These decisions not only impact the yield for the season ahead, but also impact the vigour and health of the vine in the years that follow. As such, pruning effectively requires an immense amount of thought, skill, and time in order to ensure that it is carried out effectively and efficiently each vintage year.

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