Since it's probably been a day or two since you bought it by now, you could try this trick. Bear in mind that, for me at least, it's only worked with slightly limp celery, as in it feels/looks okay, but it's not really crunchy enough to eat raw anymore.
Slice the bottom off, put all the stalks in a vase, and immerse the bottom few inches in clean water. Leave in the fridge for a few hours, and the celery will absorb enough water to make it crunch again.
This won't work for as long as a month, but I thought I'd put it out there becauase I heard it on CH a few weeks ago and it worked for me.
What to do with it:
1) Braise whole celery stalks in chicken broth seasoned with thyme, salt and pepper. (I usually use the low-sodium broth in cooking, so I can control how salty the end-product will be.) Makes a nice side dish with dinner.
2) Eat it raw with onion dip, hummus or ranch dressing or whatever your favorite might be.
3) Slice it and toss it into your mixed-greens dinner salad.
4) Chop it up and add it to egg salad, tuna salad, chicken salad, etc.
5) Fill raw stalks with a combination of bleu cheese and whipped cream cheese. Smooth peanut butter works as a nice celery stuffing, too.
How to make it last a month? I have to admit that you've got me there. But we love celery, so it doesn't last that long in our house.
And, with the cream cheese on celery, dot in a row of brined capers, too.
Or, at the Montage the other day, they sliced the celery lengthwise very thin (like a plank of wood) and used it for tiny spoons of caviar.
Garnish a shrimp cocktail with the celery end leaves.
Make a mirepoix, portion it out into freezer containers, and freeze until needed for soup, sauce, or recipe. See, http://www.foodreference.com/html/fmi...
You could try braised celery. I just got Julia Child's Mastering the Art of French Cooking, which has this recipe. I remember Julie Powell (of the Julie/Julia Project) saying this recipe was a lot better than you'd think it would be.
My mother taught me this (so I thought) corny trick, and it REALLY works.
Take the celery out of the plastic bag, and totally wrap it tightly in aluminum foil. last more than a month, for those of us who only use a few stalks in soup, and such.
I use more when I make Vietnamese Hot and Sour fish soup, and i try to remember to chop in a stalk with other soups as well, to increase their health and fibre quotient...