I have several fruit trees (Apple, Cherry, and Peach) that all have an identical growth on the bark. It looks like a fungus to me, but I'm uncertain of the exact identification and what to use to treat it. Could someone identify this and offer a recommendation for treatment?

diseased apple tree


2 Answers 2


That is lichen, which is not detrimental to your tree's health (it's not a parasite, it lives off of photosynthesis). This is normal, no need to worry.

  • 3
    Thank you, that explains why I was having a difficult time finding it in the disease lists. The second link you provided was especially useful, the take-home message being that the presence of lichen is a good sign because it is an indicator of a healthy environment.
    – Parker
    Commented Jul 10, 2015 at 1:13
  • Or old age...make sure there are no constrictions such as tags, wire...that might compromise the vascular system of this tree. CUT them off. Make sure this wire fence is not touching the bark. Make sure that the line between roots and bark is respected...soil, mulch CAN NOT get up on the bark above the line where roots end!!!
    – stormy
    Commented Jul 11, 2015 at 20:40

Yes, It is a lichen. It belongs to Parmeliaceae family. The picture is of poor quality, but it could be Parmelia saxatilis if there are some isidias, or Parmelia sulcata if there are some soralias (on the thallus).

Lichens are not a problem for your trees, they are in fact constituted of a symbiotic association between a fungus and a photosynthetic algae (it is the mushroom that invented agriculture!).

Some species are valuable to assess the air quality. Generaly yellow species indicates poor quality and air pollution...



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