To clean celery, cut off the base and leaves, then wash the leaves and stalks under running water. Cut the stalks into pieces of desired length. If the outside of the celery stalk has fibrous strings, remove them by making a thin cut into one end of the stalk and peeling away the fibers. Be sure to use the leaves—they contain the most vitamin C, calcium and potassium—but use them within a day or two as they do not store very well.
Celery should not be kept at room temperature for too long since, because of its high water content, it has a tendency to wilt quickly. If you have celery that has wilted, sprinkle it with a little water and place it in the refrigerator for several hours where it will regain its crispness.