Saturday, June 2, 2012

Winter Dessication of Pine Trees by Irene Shonle

Dry dead needles on windy side of trees

We had a dry and windy winter  this year (thanks to  La Niña).    Pine trees are really beginning to show the effects of their winter struggles, evident  in the dead and dying needles in patches and clumps on the outer edges of the trees.    The effect is especially pronounced on the windy and south sides of the trees.   It may look alarming, but it doesn’t mean the tree is dying, and it isn’t a sign of pine beetle.  (With pine beetle, the entire tree would turn yellow to brown, not just the exterior needles). This happens because transpiration from needles or leaves occurs when winter days are warm and dry. Small "hair roots" may die in dry soils leaving roots unable to replace lost leaf moisture, and this results in needle death.   Once the needles fall off, the trees will look much better.  For more information, please go to: