Yellowing usually means too much moisture. Is the area well drained? If you're providing extra water, stop. They dont need any, can survive on rainfall alone.

Jen

I too have 2 recently planted Blue Rug Junipers (planted 1 month ago) and they are turning yellow. I believe I have over-watered though I've only watered them twice, the watering was thorough because I was told that with newly planted 'plants' that they need to be watered more frequently until they are established. WHAT DO I DO IN THE INTERIUM? WILL THEY EVENTUALLY DRY OUT AND NOT DIE? I am going to check for mites or whatever but if it is not that, then I guess it is over watering. I am really sick about it.

Be sure, also, that they have soil that not only dries out completely between watering, but that gives an acid reaction.
Hollytone, or some similar acidifying fertilizer, very sparingly applied, may provide the chelated Iron that many plants seem to need to keep them from yellowing.
I never allow any lime to get near any plant that seems to need a soil pH below 6. That includes most evergreens, and most plants of the Heath Family.