We have a 60 foot redwood tree in our backyard, in Beaverton, OR, and have...
We have a 60 foot redwood tree in our backyard, in Beaverton, OR, and have noticed portions of the branches/leaves turning yellow and brown in recent weeks. Does it have a disease, and if so, how can it be treated, considering the height? We don't want to lose this tree. Thanks for your help! Sorry for the duplication, as I forgot to include my email address when I first submitted the question.
Washington County Oregon
Thank you for your question, and sorry to hear that your tree is showing signs of stress. After reviewing your pictures, my first thought is that this is drought damage. This is our third dry summer in a row, and we have seen symptoms of drought stress and mortality on various species throughout the Willamette Valley. In some cases, it takes one or two years of water stress for the tree to show symptoms. There is an article on the Tree Topics blog that provides some more information about drought this year in our region: http://blogs.oregonstate.edu/treetopics/2016/05/26/effects-drought-continue-valley/
There is a small chance that you may be dealing with some light insect damage. Take a close look at the damaged branches and see if you find insects, eggs, insect excrement, signs of insect feeding, etc. (Keep in mind that drought-stressed tress often attract secondary insect pests.) If you see anything, please take pictures and respond to this message.