What has good nitrogen in it for celery?
Why Is My Celery Leaves Turning Yellow?
Certified GKH Gardening Expert
Here are some reasons your celery's leaves might be turning yellow:
Low nitrogen can be one cause. Compost is a great source of nitrogen for celery. An alternative is to add 1 tablespoon (15 ml) of a 10-10-10 fertilizer next to the plant every 3 weeks, then water it in. Make sure the fertilizer doesn't directly touch the stem.