Quercus douglasii and Quercus lobata
This photo shows a classic comparison between the California Blue Oak (Quercus douglassii) and the native Valley Oak (Quercus lobata). The Blue oak in the foreground, shown previously, is a particularly symmetrical specimen. In the foggy background is a Valley Oak, showing its typical craggy and pendulous growth habit. Valley Oak can be a fast growing oak under the right circumstances - up to seven feet has been observed in a single year on Valley Oaks on the Dish, grown directly from acorn into a five-foot Tubex tree shelter, back in 1992. This growth speed was quite shocking to the tree surveyors at the time, who had always heard that oaks are slow growing. The pendulousness of some individual Valley Oaks can radically slow their vertical growth.