Impossible to tell (much of anything) with the information provided. Pictures, details of maintenance (watering, pruning, etc, etc), description of any changes (weather, exposure, insect damage, etc, etc), and another other information you might be able to provide might allow us to at least guess what might be happening. Right now we're playing pin-the-tail-on-the-donkey, and not only are we blind-folded...we don't even know if there is a donkey present!

where are you .. is it fall or spring ... any recent cold snaps ...

how long have you been on the property ... do you know its history for the last year ...

one thing for sure... its stressed.. not hungry ... fert is not the answer ...

lets see some pix ...

how do the growth tips look ... compared to the rest ...

no evergreen plant holds its leaves forever .... are these older.. interior leaves???

ken