Xtremehorticulture

White Fuzzies on Ash Growth

Q.
I have a 6-8 yr. old ash that has this white powdery looking substance on the
newer growth. Can you tell me what it is and how to eliminate it. 

Picture from reader of white growth on ash


A.  I have seen this kind of “growth” on several vegetables and herbs as
well including peppers and basil over the years. I have sent pictures of these
two a good friend of mine
, a well-known horticulturist in Arizona asking
him what he thought they were. I could tell he was giving me his best guess as
well but I don’t think he was very sure himself. 

Here is a post on something
similar I made back in 2012


Although
not exactly the same thing it appears to be more insect related than disease or
physiological in nature. I wish I could give you a better response than just to
keep your eye on it and let me know if things get worse. If things do get
worse, then I would direct you towards a soil applied systemic insecticide for
the tree if it is needed. That is the best I can do for you at this point.

Perhaps some are other readers might hazard a guess?

2 thoughts on “White Fuzzies on Ash Growth”

  1. I have seen those too in Phoenix every year either now or when I am dormant pruning. I have used a 16X hand lens and rubbed them looking for goo or some darned reaction. I too have no idea but also believe they are insect eggs or insects of some kind. I doubt they harm anything. I thought they might be wooly aphids, some sort of scale or eggs. I just cannot tell enough to rule out anything.

  2. I'm sorry, I just sent you an email about this, not realizing there was a comments section.

    Anyway, I always thought this was powdery mildew, no?

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