[NickNerdy]

From a nytimes article "the valley is the world’s largest patch of Class 1 soil, the best there is. The 25-degree (or so) temperature swing from day to night is an ideal growing range for plants. The sun shines nearly 300 days a year. The eastern half of the valley (and the western, to some extent) uses ice melt from the Sierra as its water source, which means it doesn’t have the same drought and flood problems as the Midwest. The winters are cool, which offers a whole different growing season for plants that cannot take the summer heat. There’s no snow."