Celery needs a very long growing season which is why it’s a good idea to start celery seeds indoors at least 12 to 14 weeks before the last frost date for your area. For us here in zone 5b February is the best time. The seeds are tiny and can be tricky to plant, so I sprinkle them on top of my soil mix (coco coir & worm castings) and lightly cover with a little bit of coir. Once the seeds have sprouted, you can think them out or individually pot each seedling. For me, I leave them in a medium si