Celery is an ancient crop. The seeds are a bit slow to start, but once the transplants are tucked in the garden, this potassium-rich vegetable grows very well in Atlantic Canada. Growing Tips: Celery should be started indoors in early March, 10 to 12 weeks prior to setting out. To encourage germination, soak the seeds overnight. It also prefers a rich soil, so if fertility is a problem, incorporate some organic matter into the garden before planting. Space the transplants 30cm (12”) apart and mulch well.