Understanding site "capacity": the key to farming grapes successfully in the foothills.
 

Capacity is a term that refers to the productivity (growth) of the whole vine and includes the vigor-inducing potential of your site, combined with the growth properties of the variety and rootstock. Vigor is defined as the rate of shoot growth, as measured by change in length over time. Grapevines are generally vigorous-growing plants, but there are many ways this vigor can be manipulated to create vine balance, given the inherent characteristics of the vineyard site. Understanding your site capacity is the key to selecting the appropriate rootstock, variety, vine and row spacing, irrigation scheduling, and trellising type for your parcel, allowing you to adjust growing parameters to work with your site capacity in order to achieve the desired vine balance.
 

Understanding the capacity of your site is the first step to achieving vine balance, quality grapes and quality wine!

Site capacity is mainly indicated by the soils on your site, and the site microclimate.

• Remember, foothill grape growing sites are highly variable! Each parcel needs to be evaluated for its potential.
• Soils can be deep and nutrient-rich, such as many volcanic soils, or more shallow, (say, at the top of a slope) or/and lacking some key nutrients, such as granitic soils typically low in phosphorus. Visit our page on soils for more information.
• Microclimates also vary greatly. Depending on elevation, but also slope and aspect can vary on a single parcel. Weather conditions are important in considering rootstocks, varieties, and location of vineyards. In particular frost can commonly occur in the foothills. Visit our page on frost protection and frost recovery for more information.
• The site capacity will also be dictated by the availability of water and water quality of a site. Testing your well or source water can be important in determining site capacity.
• The spacing of vines and training system will also determine site capacity. Types of training systems include: vertical shoot positioning (VSP), geneva double curtain (GDC), single high wire trained, lyre divided canopy, or head-trained.