I have a very large (12-15 ft high) douglas fir hedge surrounding my 1/2 acre property. Three of the individual trees in the hedge (all next to one another) and a nearby spruce are dying. Last year they produced lots of cones and the tops started dying and turning black. This year it looks like they are in real trouble. Could this be root rot? How do I identify exactly what it is? What can be done? Perhaps of note is that there are some exposed stumps nearby from trees that were cut down before I bought the property (less than a year ago).
I would suggest you get a few different proffessional tree care people to come look at your hedge soon. Arborists, and tree spraying companys, hear them out and try to find a place to take a sample for daignosis of the root and branch from dying tree, not the dead ones. Sounds like a hedge you wouldn't want to lose, if needed there is a root fungicide called ridomil. Look to see if it is a low spot where water my sit, where the trees are dying? good luck , Jim.
Maybe something for you here. Scroll down to Fir, Douglas. http://plant-disease.ippc.orst.edu/...=Select&host_text=fir,+douglas&submit=++Go!++
Jim, I dont believe Ridomil is registered for homeowner use. I would gesticulate that it may be a drought issue rather than a root rot issue. and the fact that Douglas Fir really isnt considered 'really big' at 15 feet. It is a large tree destined and genetically designed to attain a 100 feet height and then some. The stresses of being maintained as a hedge with accompanying water stresses of being crowded with its neighbors in an unnatural setting, make me lean to the lack of water vs excess moisture thoughts.
Too bad we don't have video so we can see you gesticulating. 3 firs close together and a spruce could be something like honey fungus. All anyone here can do is throw out possibilities. If there is a bigger, non-hedged tree nearby that is overtopping them and/or outcompeting them in the ground then that could have finally done them in also.
Your right Ron all any one can do is throw out gestications without actually looking at the hedge and surrounding area. Ridomil can only be applied by a licenced applicator. But plenty of tree proffessionals don't even know of its existence. We have had serious drought conditions in the summers 20,03,04, and were brutal on trees, and the symptoms seem to be worse this year then last, around the lower mainland. I haven't noticed it to be so severe on evergreens though, do you think they are just more drought resitant? Back to the tread content, I've just commonly noticed that when evergreen hedging start to die 1-2-3 in a row like that, it often starts at a low point in the yard. And would think if it was caused by drought it might be more spuratic throughout the hedge showing signs of what would look like tip blight? This is just off the top of my head from past diagnosis. And being that the tops were dying and turning black, like a fire blight, I would be concerned with drainage problems and root rot. Olda, definately get it properly diagnosed on site. Jim
Thanks for all your insights. Does fire blight look alot like the branches have been burned? When I crumble the blackened parts between my fingers it is hard to believe it hasn't been burned.
I'm sorry, I never heard of fire blight actually effecting douglas fir, I just meant that the symptoms may look like it. Fire blight usually effects apples, pears, and various deciduous plants. I would imagine that the blackening is just the after effect of dying not the cause. I wouldn't wait to long to get your hedge looked at, its a long way around a 1/2 acre to be replacing all them. Good luck,, Jim
