Answer: Based on your description I am not certain what is happening to yur spruces, however in hot weather they are often attacked by mites, often on the side where heat is reflected back at them off a building or by pavement. I would suggest you consult with your local county extension to obtain a specific diagnosis, and based on knowing that, decide how to treat them. If a chemical control is needed, they will have the most up to date information on what to use and how/when is the best time to apply it for maximum results. With mites, it is important to act quickly. Good luck with your little spruces.
Q&A Library Searching Tips