Yews Have Sticky Black Substance On Needles

Question From: C. Yerkovich - Lake View, New York, United States
Q: I have a row of yews. Some of the needles has a sticky, black substance on them that seems to be hurting them. Do you know what might be causing that substance to appear on the needles and, if so, what I may be able to do about it to help the plants? Thanks! Carl

A: Carl, I believe the black sticky substance is sooty mold. The problem is caused by either aphids or scale that produce a honey dew - it's sticky and the black mold grows on it. To get rid of the problem you must treat the bugs. Neem oil is a good choice. Use according to package directions and repeat the application as directed. The sooty mold will eventually wash away. Best And Happy Yardening, Nancy