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Grape Growing

All our vines are trellised using a VSP (vertical shoot positioning) configuration and are planted in a 9' x 5' row x vine spacing grid.  This T-shaped vine geometry involves a 3' high vertical trunk, two opposing horizontal side-arms (called cordons) on each of which about half a dozen vertical spurs (short stubs with 2 buds on each) are located and from which 4 green shoots grow vertically (2 per bud) and near the bottom of which the grapes will grow.  In the winter & spring following harvest these shoots will be eventually pruned back so as to again leave 2 buds on each spur and the cycle will start all over again.

Frost protection measures are required due to the late spring frost risks mentioned above.  We use a pruning method called double-pruning where the first pass, done in winter, leaves foot-long canes rather than the usual short 2-bud spurs.  The ruse behind this approach makes use of the fact that bud break first happens near the end of cut canes and this delays bud break for the 2 buds of interest closest to the cordon by up to a couple of weeks, at which point the over-long spurs are cut back just above these 2 buds.  An overhead sprinkler system (same idea as in Florida's orange groves, using the insulating properties of a thin layer of ice) can also be utilized as well as spraying of a product called Frostshield, also forming a thin insulating layer over the buds. 

Pierce disease and phylloxera which have caused ravages in the rest of the state are practically non-existent here (only one case of phylloxera reported and no Pierce disease).  An 8' fence surrounds the vineyard to protect it against the large deer population in the area.  Another animal threat comes from gophers and special control measures are needed to control their impact.  Mildew control is done using weekly or bi-weekly sulfur applications up to veraison (when grape color changes from opaque green to blue/purple or translucent gold - a truly magical moment) and herbicide is applied twice a year.  Mowing passes are also done at the beginning of the season, until it gets too dry and brush fire risks get too high.

Irrigation water comes from NID water (19th century ditch network collecting/channeling melting Sierra waters and originally used for mining operations).  This water is sold to us by the miner's inch, which is the size of the pipe opening we use to tap into the nearest NID ditch located about 200' higher than our property and providing more than adequate rates & pressure.  Irrigation is carefully controlled so as to not over water vines which makes vegetative growth too vigorous at the expense of fruit growth (can actually impart a vegetative character to grapes).  Mature vines are even water-stressed during part of their growing season, again to ensure a vegetative/fruit balance optimal for the production of top quality grapes. 

To keep the leaf canopy open (reduces mildew risks and increases sun exposure), various green shoot/leaf pruning/tipping passes are done throughout the summer to remove lateral shoots and limit the vertical growth of the main shoots.  The trick here is to keep just enough leaves for the photosynthesis activity level required to ripen the fruit.  Fruit in excess of the desired crop level is also dropped as soon as formed. 

Although a mature vine can produce well in excess of 25 pounds (and even up to 50 pound for head pruned vines) of low quality grapes if left on its own, the above measures limit the crop level to the 5-10 pounds range per vine to concentrate flavors/aromas and ensure the production of top quality grapes.