Question
QUESTION: Hello David! I got a problem with different pine type trees around the house. I live in Cincinnati, Ohio. Needles on one big old tree (looks like Christmas tree)turned yellow after this summer. I tried to water it in late summer since I thought it happened due to drought in the area. It did not stop and the tree now is mere than half yellow. It is spreading up the trunk.
Another small Blue Spruce which is about 4 years old developed the same kind of a problem. It developed a yellow spot close to the top, which got bigger. Now all needles, which are not yellow, look much lighter then on the other the same age and type tree which is in good conditions.I planted them at the same time about 12 feet apart.
On the front yard I also have 6 pine shrubs which are 2 years old. On few of them separate branches turned yellow also.
I hope you will help identify the problem and advise if I need to get rid of these trees to stop spreading of this infection.
Thank you very much,

Val.

ANSWER: There is a fungal disease of conifers that causes a needle and twig blight.  It is caused by the fungus Cercospora.  The disease typically causes the needles to turn yellow and then to brown.  Several other fungi can also casuse this problem.  A dought period would have made the trees susceptible to this type of problem.  I would prune out the affected areas in the trees and burn them if possible, but definitely dispose away from trees.  When it warms up enough for the trees to begin to grow I would treat with an all purpose fungicide called Daconil (chlorothalonil) or Kocide (copper hydroxide).  Make two applications about 10-14 days apart spraying the entire tree, especially on the inside of the canopy, where the problem usually starts.  Make sure the trees do not become drought stressed.  Observe the trees over the next month or so for evidence of the disease.  If you see symptoms, treat again.  I hope this helps with your problem.  Good Luck.

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

QUESTION: David, thank you for your quick response.
I noticed that this decease continues spreading on small shrubs right now. New branches continue turning yellow during winter. Would you suggest I prune them now or wait until spring? Also, can the affected branch eventually recover (after applying chemicals)?
Regarding the oldest tree, which is about 40 feet high and more than half yellow: should I cut and burn it or leave as is and see what happens (spraying it with chemicals is out of questions)?
I appreciate your time very much

Answer
Lets start with the spreading of the yellowing branches on different types of conifers.  My first inclination is to believe that environment may be the main culprit here.  You mentioned having a drought last summer.  This could be the main cause of all of this problem.  I would go to each tree or shrub and take a knife or your fingernail and scrape the bark in the yellow or brown area.  If there is green or white tissue underneath, that is an indication that the branches are still alive and I would not cut them off.  If there is no green or white living tissue underneath, then, yes prune them back to where you do see healthy tissue.  Then I might wait until spring and see what happens.  The fungicide treatments will not hurt anything, but may be unecessary in your case.  It is a routine treatment we recommend for dying and diseased twigs.  As far as the big tree--- wait and see what happens this spring.  On all plants look for cracks in the bark at the soil line--- if they occur, this is an indication that the trees and shrubs have experienced cold injury.  You will have to wait to see what happens with all of these plants in my opinion.  Take a look and then reply back with pictures if possible and we will move deeper into the cause of the problem.  Hope to hear from you soon.