I live in Milwaukie surrounded by large red cedar, sequoia, fir and oak trees. A month or two ago, we noticed a dry patch in the middle of our Giant Sequoia tree. Over the last 3-4 weeks, it has spread to the majority of the upper third of the tree. I had an arborist look at it today, and he recommended that I contact you all. We do not routinely water this tree since it is so huge. in the fall of 2011, there was some work done in the roadway near the tree to improve the drainage from the house across the street from us. The arborist today thought it looked serious and thought it might be due to heat stress, chemical cause (gas leak or herbicide) or fungus. We do not use herbicides but both neighbors across the street do seem to. The arborist saw no signs of fungus, but he did see marks from whoever climbed the tree using climbing spurs to remove the lower limbs which he discouraged. this was done prior to our purchase of this house/lot in 2011. Thank you for any information that you can provide. I am worried about the progression, and I love this beautiful tree. I am also worried about what may happen to the tree and the risk of it falling if this continues.
Clackamas County Oregon
Thank you for your question to Ask the Expert.
The cause of the problem on your tree looks to be heat or water stress. Watering an older tree of this size is not necessary since it is so well established. It is possible the recent construction disrupted the root system of the tree or altered water availability in the soil, which could have prompted the problem this year. It has been a warm summer and many conifers are showing signs of water and heat stress
Unfortunately, there is not much that you can do about this situation other than waiting to see how the problem progresses or if it gets better early next season. Adding water could help the tree overall, but will not make the foliage that has turned brown green again. That will not occur until next year if at all.
Please let me know if you have further questions.