norway spruce dying
we have one douglas fir that has died this winter and now we suspect several of our norway spruce are thinning (that is, appear to losing needles). Is there a specific fungus we should be addressing to guard against further damage?
Carroll County Maryland
Please send us photos of the whole spruce tree, around the base of the tree, and affected needles so we can see what you may be dealing with.
In general, Douglas fir is not well adapted to our area and grows best where there is an abundance of high atmospheric moisture. It fails on dry poor soils and injured by high winds. They can be subject to a needlecast disease. There is no chemical control. http://extension.umd.edu/hgic/topics/evergreen-needle-cast-diseases-trees
Yes, this looks like needle-cast disease, according to our plant pathologist. (See above link.)
However, this looks more like Colorado spruce than Norway spruce.
The needle-cast fungus has been prevalent the past year because of the abnormally high rainfall (the year before that was wet, too.)
You do not need to do anything to your spruce at this point. They look well spaced, so they get fairly good air circulation to dry foliage after rain. They are budding out (some earlier than others.)
Do be sure that mulch does not contact the trunks (or branches). It should be kept back several inches. Also, keep mulch to no more than about 3" deep. Air circulation about the base of the tree's limbs is important, too.
Thank you for your prompt responses and for the good information.
Your points are note, and I am going to trim and low-lying branch, where needed, to improve the air circulation.