June 20, 2019
In Napa Valley this time of year, you’re likely to see vineyard crews scattered amongst the vines. “What are they doing,” you ask? They are Shoot Thinning and Leaf Pulling.
Shoot thinning and leaf pulling are part of overall vineyard canopy management, as seen here in Sauvignon Blanc vines at our Soliloquy Vineyard. Learn how our Soliloquy Vineyard is entirely unique to Flora Springs and distinct from more common Sauvignon Blanc vineyards in Napa Valley.
Shoot thinning is a process in which any unnecessary shoots are removed—typically those in the lower regions of the vine. Removing select shoots allows the vines’ energy to be directed towards the primary shoots, which will ultimately bear fruit.
Leaf thinning is conducted for a variety of reasons, particularly in wet years like this one when the canopy tends to be vigorous. Too much vigor can lead to vegetative characteristics—which we don’t want! Removing the leaves curtails this issue. Leaf thinning also opens up the canopy, allowing increased air flow and quicker drying in the event of morning dew or rain, and to prevent mildew in humid conditions. This opening of the canopy also increases light penetration—which is needed for photosynthesis. Sunlight exposure improves grape quality, protects the berry, and also elevates the phenols and polyphenols that are responsible for the color, taste, and flavor of the wine.
While this work is being done, the crews are also positioning the shoots. The shoots may be 24”–36” at this point. If we are working in a vineyard that has a vertical trellis system, there will be a series of horizontal wires running from one end of the row to the other. As the vine grows, the shoots will be tucked into the wire trellis to allow for what is commonly referred to as VSP, or vertical shoot positioning. This allows further opening of the canopy. There are other types of trellises, but VSP is the primary system implemented in most Flora Springs vineyard blocks.
After the initial thinning pass, each block will be monitored in the weeks to come to determine when/if additional passes are to be made.