Question
QUESTION: I have a 10 year old sour cherry tree that is growing next to a wooden fence.  Last year I noticed the trunk of my tree had a green fungus growing on the bark. Upon further investigation, I noticed what looked to be the  same fungus growing all over the fence.  I sprayed the tree and fence with fungicide late in the summer.  This year I noticed the tree has many dead spots.  Many of the limbs affected have some dead branches and some live branches on them.  I have also noticed on some of these branches are knots that are oozing sap.  also the green fungus from last year is still on the trunk of the tree and has now moved up to the limbs.  What kind of disease or diseases am I dealing with and how can I save my tree?  Thank You!

ANSWER: HI there: What you have on your is Lichens they are organisms consisting of a fungus and a green or blue-green alga growing together in a mutually beneficial, symbiotic, relationship. The entire structure, called a thallus, is so different structurally from either of its partners that microscopic examination is necessary to distinguish the fungus and the alga.

The fungus obtains water and minerals from the air and the material it is growing on. The alga provides carbohydrates and vitamins. Some blue-green algae fix nitrogen that is used by both the alga and the fungus. Nitrogen is also obtained from bird excrement, organic debris, or plant leachate.

Lichens may be flat, leafy, or branched and hairlike. All three forms occur on tree bark as well as on rocks, soil, and other substrates. Colors may range from white to gray, red, green, yellow, and black.

Although lichens grow on tree bark, they are not parasitic (disease-causing organisms), and do not harm trees. The fact that lichens grow rapidly when exposed to full sunlight may explain their profusion on dead trees. The one conclusion that may be drawn with certainty from lichens on trees is that the air nearby is relatively pure. Most lichens will not grow in a smoky or polluted atmosphere.
So please,don't kill them. Hope this helps,Bill



---------- FOLLOW-UP ----------

QUESTION: Why does my tree have all the dead branches and oozing sap spots?  Can I save it?  It looks like over 1/2 of it is dead now.

Answer
Hi. Chances are you have peach tree or lesser peach tree borers in your tree.
PLANTS ATTACKED: Peach, plum, cherry, etc.

DESCRIPTION OF DAMAGE: Very similar to that of the peach tree borer which is in
the lower part of the trunk but it
attacks the upper part of the tree and its branches. Frequently masses of
resin are found in the crotches of trees. Damaging stage - larvae.

IDENTIFICATION: Larvae are white with brown heads, 1/2 to 3/4 inches long. The
adults are metallic blue-black with pale yellow markings on abdomen.

LIFE HISTORY: The partially grown larvae overwinter in the inner bark of the
tree. The larvae start feeding early in the spring,  Egg laying
takes place during the summer and early fall in the cracks and crevices of the
bark. The hatching larvae bore into the bark and begin development prior to
cold weather. One generation per year.

CONTROL: Although spraying or painting of the infested tree in September or
October gives the best results, it may also be applied in April.

Treatment Options
The insecticide product available for home use is Bayer AdvancedGarden?Tree andShrub Insect Control.
For additional treatmentoptions, contact a local professional arborist.
Caution: read all label instructions before using any pesticide, avoid skin
contact, and store pesticides  where children cannot reach them.
Hope this helps,Bill