Answer: Unfortunately, based on your description I am not certain what has happened to your trees. The spruce might be suffering from a disease or from an insect such as mites, or it maybe related to winter sun scald damage or damage due to de-icing salts or herbicide contact or something like that. The locust sounds as though it may have suffered dieback, possibly due to poor rooting or over or underwatering or a poorly drained site. It is very difficult to diagnose this type of symptom long distance because there are so many different potential causes. If the trees are under warranty, I would strongly suggest you consult with your local professionally trained nursery staff and/or your county extension to try to determine what is happening to them and based on knowing that, how to proceed. I'm sorry about your trees.
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