This recipe uses fennel stalks instead of celery. Use celery if you don’t have fennel stalks. Also, substitute chopped beet greens (tough stems removed) for the chopped cabbage, if you have them.
Another substitution for the cabbage is chopped sauerkraut. You may need to reduce vinegar if using sauerkraut if you don’t like your soup really sour.
Find it online: http://shiftycrafty.com/classic-russian-beet-soup-borscht/