In the full heat of summer, the vines are growing steadily and berries are beginning to form on the vines. It’s time to set the stage for harvest. Canopy management is now more important than ever to maintain the ideal microclimate on the vine, and so begins the process of leaf pulling.
Pulling leaves from the growing canopy thins it out, which allows sunshine to reach the grapes and ripen them. A thinner canopy also improves airflow around the tightly packed clusters of developing fruit, which helps prevent mold growth in the cool, damp climate of Oregon’s Willamette Valley and keep pest pressure low. However, care must be taken not to remove too much--when temperatures rise, the grape are at risk for sunburn without some shade coverage provided by leaves. Too much sun can also lead to overripe flavors.
Like most vineyard tasks, leaf pulling is labor-intensive. Every leaf is pulled by hand and selecting which and how many leaves to pull takes skill and experience. The vineyard crew pulls leaves away from the area just above the vine’s cordon, or arms, where the clusters are growing. Many of our crew members have been with us twenty years or more, so they move quickly and efficiently through the rows under the supervision of Vineyard Manager Miguel Ortiz, thinning the canopy perfectly and ensuring beautiful fruit in the fall.
Also called basal leaf removal or cluster-zone leaf removal, leaf pulling is such a crucial part of vineyard management that Oregon State University has been conducting experiments to determine the effects of leaf pulling on grape development. They have found that leaf removal noticeably enhanced color and aroma in fruit more than no leaf removal.
With just the right amount of sun and air, the grapes at Ponzi Vineyards are progressing beautifully.
Read along as we follow the vineyard throughout the year in The Vineyard Series: