|We live in the foothills of the Columbia River Gorge, and are proposing to put in a small vineyard that would get 70% sunlight, during the months of July August and September. Temperatures average in the high-70s.
Question: What seedless variety of grape would be tolerant of a mix of sunny and rainy days typical of the Columbia River Gorge, mid-elevation?
|As you probably know, grapes need a certain number of accumulated heat units in order to ripen. Grapes will not fruit well unless they get full sunshine all day, so if you can increase the sunlight, you'll have a better yield. I expect that your area will have an average heat accumulation of less than 1500 units, which means you'll have more success with the very early cultivars like Lynden Blue, Canadice and Reliance. The only seedless variety that will produce reasonable crops in your area is Interlaken. These are all dessert or juice grapes. If you're interested in European grapes for wine, try Siegerrebe or Madeleine Sylvaner. All of these cultivars are available from Raintree Nursery, 391 Butts Rd., Morton, WA 98356. (360) 496-6400.|