Blue oak (Quercus douglassii) are native to the hot, dry slopes of California’s interior valleys. They survive drought through a series of mechanisms, including the blue, waxy layer atop their leaves which helps reduce water loss in summer.
They need very little water. Blue oak will survive on 15 – 30″ of rain a year. Too much water is what kills them. Bartlett Tree Research Laboratories lists excessive watering as the leading killer of established Blue oak in the landscape.
In a normal year, Blue oak leaves turn golden yellow and pastel pink and orange during fall. However, in hot, dry years like this one, leaves achieve early dormancy, turn color suddenly and drop. That’s happening this week in the Sierra foothills where suddenly Blue oak are near peak.
Blue Oak, Sierra Foothills (Near Peak – 50-7%) GO NOW!