My father used to buy celery in a grocery store owned by a Greek. I don't know where the celery was raised, but the stalks were almost two feet long, which included the root.
That celery had been lovingly tended, the soil and mulch having been heaped up to support and blanch the stalks. You just can't buy celery like that these days. If the stalk is green, the celery is going to be bitter. And today there is no root included, which used to be the best part, except t;hat they nailed the roots together, and my father told me to cut away the nail holes, because the harvesters held t;he nails in their mouths before using them. The rest of you self-proclained gourmets have never had any good celery.