Autumn 2014-2015 Yellow Needles on Ponderosa Pines

On Nov 9 the daytime high temperature was 73° F. By Nov 13 the nighttime low temperature was down 84 degrees to -11° F. Bruce Benninghoff (the BeetleBuster’s expert consultant ) determined that the very cold weather of Nov. 13 was responsible for damage (observed as yellow needles) to many Ponderosa pines that residents of PBH have noticed. Indeed many trees, not just Ponderosas, were caught off guard: "The reason that the Nov. 13 deep freeze caused so much damage is that it had been so warm until that time. The trees (all kinds) and shrubs had not completed the transition to winter hardiness. Sudden transitions cause damage." Whether the trees will recover is hard to determine (depends on current and future water etc.). We will just have to watch them over the coming year.

Note that the above yellowing of needles is different from that occurring on many trees along the side of the roads in PBH. For example a lot of trees along Timber Lane do not look very healthy. Their issues are likely due to the accumulation of chemicals applied to the roads. (But the rapid deep freeze of Nov. 13 would not have helped them.)