Is the blue color on a blue spruce tree caused by a fungus?
Colorado blue spruce [Picea pungens] is the native, state tree of Colorado and of Utah. And it grows best there. Elsewhere, it’s susceptible to fungal disease. But its color isn’t caused by fungus. Instead, it’s caused by the waxy silver blue powder, ka bloom, that’s naturally formed on the needles. The bloom can be wiped off, or washed off in intense rain and snow fall events. In fact, gradual loss of the powder over time may lessen overall color with age. But the color’s genetically determined, and therefore not caused by cultural practices or environmental stresses.
