|On my two Hemlock trees there are white spots on almost every branch. They seemed to spread from the bottom up. What is it and how do I stop it?
|Based on your description it is difficult to give you a definite diagnosis of, or a solution to, the problem. However it is possible that your trees are suffering from hemlock wooly adelgid and, in some cases, horticultural oils can be used during the winter months to control this serious and potentially fatal insect pest. You might wish to contact your County Extension for a positive identification of the pest and any suggested means of its control. Their telephone number in Lehigh County is 391-9840.