Grape vines reach their full expressive potential on the steep canyon lands if Windhorse Vineyard, nourished by ample winter rains, and bathed by hot summer sun. The strong sun exposure from cloud-free summer days, the day length of almost 17 hours in mid-summer, and the dominant westerly aspect of the vines at Windhorse vineyard lead to growing season temperatures that allow us to fully mature and harvest even late-ripening red grape varieties such as Zinfandel. In fact, over the planting zones of the vineyard, we have measured an average of about 2950-3000 heat units or growing degree days. At the same time, the low relative humidity in summer, high elevation, and cooling mountain winds at sunset lead to cool nights that preserve freshness and acidity in the fruit that is so essential for fine wines.

The vineyard receives about 18 inches of precipitation annually, but just as important as the yearly total is the seasonal pattern of rain and snow: The yearly pattern of precipitation on the vineyard and in the Columbia Gorge is known as a XERIC moisture regime where about 80% falls between November and May each year. This is perfect for wine grapes as the winter rain and snow fills the soil profile with water so that the grapevines are fully supplied with water as they break dormancy in April and grow their leafy canopy and set fruit in May and June. By this time, the native soil moisture is typically almost depleted and typically no more rain will fall until late October, but this is what’s great about the Xeric regime because it’s at this stage of a grape vine’s season that low soil moisture combined with strong sunshine and wind stress sends the signal to the vines to shift the focus from leaf growth to filling out the berries and ripening fruit.

Dry soil conditions starting in early summer allow ‘controlled deficit irrigation’. This is the application of judicious amounts of water from drip irrigation, that are just enough to maintain photosynthesis for berry development but induce mild stress in the vines to slow and then stop shoot development and leaf expansion. In fact, the Xeric pattern of winter wet and summer dry almost exactly mimics the pattern in areas such as the Transcaucasus region between the Black and Caspian seas and the western Mediterranean region where the wild Vitis vinifera (to which all modern wine grape varieties belong) is known to have originated.

Our vineyards currently extend up to 1200 feet in elevation and future plantings will extend up to 1325 feet, placing the vines above killing winter freezes that can occur at elevations below about 600 feet in this valley when Arctic cold air sometimes pools in winter in the lower elevations.