Celery is one of those things at my house. I buy it if I'm making stuffing or Bloody Marys. That's about it.
I bought it in mid November for my Thanksgiving stuffing. This is what it looked yesterday, in mid January.
You know why it is still fresh, green and crisp after 2 months in my fridge?
Because I stored it tightly wrapped in foil.
I have had celery for 6 months that still looked (and tasted) like it had just come off the produce stand. For whatever reason, wrapping it in foil keeps it fresh for a long, long, long, long time.