dying doug fir
A few of my 8 to 10 year old doug fir have died. They have not been girdled by deer. Is there a disease affecting them in the area. Or is it possible that when spraying Crossbow near them, some of the poison drifted. I've seen no problem with my mature trees.
Clackamas County Oregon
Diagnosis of a problem like this is very difficult to do by email, not being able to see symptoms or otehr clues.
That said I have been hearing of, seeing a number of trees with symptoms of individual branches and tops dying that look pretty closely connected to last year's late summer drought conditions. Typically showing up on younger trees at this point, not the older ones. This is throughout the Valley.
This happens from time to time. I am attaching a publication from colleagues at ODF written up about this phenomenon in 2001. Take a look and see if it fits. http://www.oregon.gov/ODF/privateforests/docs/fh/InteractionOfDrought.pdf?ga=t
Cross bow is another issue. Likely different symptoms. It can be damaging to D-fir, especially in spring and early summer. One reason it is not registered for use in forestry.