|I have a green spruce (about 7' tall) planted two summers ago. I noticed last summer that some of the needles toward the inside of the tree (near the trunk) had turned a rusty-brown color. They did not fall off the tree, and one year later, are still there. Clearly, they are dead. The tree has put on a tremendous amount of new growth, and the new growth since the original planting is free any rusty needles. I plan to trim some of the sparse, ragged bottom branches out of the tree this season. Is this something that sounds familiar? There is no sign of insects, no holes in the trunk, etc. However, after the first winter in the ground, I noted some sap hardened on the trunk. I have not noted this sap in subsequent years. Any ideas?
|Unfortunately I can't give you a definite answer based on your description. There are a number of possible causes for spruce needles to turn brown and branches to look sparse including cytospora canker, needle casts, spider mites and possibly the spruce aphid. All of these would cause damage without obvious insects or holes. Another possibility is that the tree got too dry at some point during its first year, and needles died back as a result. If possible, I would consult with your local county extension or an arborist for a definite identification of the problem. Glad it's putting out such great new growth!