dormant or dying?

I have a silly question, one which I guess will be hard to answer with out seeing my plants, but I'll go ahead and ask anyway....
Is there a way to tell if your plants are sick, or if they are just going dormant for the winter? I have a few plants I am concerned about.
One is a Fragrant Osmanthus whose leaves have some brown spotting to them and are turning yellow to light green. Second my Loropetalum whose leaves are browning--the browning is not occurring uniformly, but seems to be contained to one branch. Third is a Gulf Stream Nandina whose stems and leaves dropped off the top of the plant, however the lower stems and leaves are still in tact and look healthy.
And now a question from the "I know this is dying, but is there any hope left department......" I have a Coastal Leucothoe which has lost all of it's leaves and branches. The remaining stem seems to have some green to it, however I can't tell if the green is just a fungus on the stem or signs of life. If I cut the stem, I do not see any green in the center. Bad sign? The root system still seems strong. Is there any change this little one will come back to life? Or should I shovel prune it into my compost pile?
Should I just wait these out, or should I take action if there is a disease going on?
Thanks for any advice! Heidi Raleigh, NC
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Scratch through the bark with your finger nail , if there is green under it then the stem is still alive.
--
David Hill
Abacus nurseries
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