(Apium graveolens) Moisture-loving Old World crop grown since antiquity. They are best started indoors 8-12 weeks before the last frost of spring. The tiny seeds must be surface-sown and never allowed to dry out. The young plants are set out at about the time of last frost, preferring a moister soil than most vegetable crops, and very rich in organic matter. Requiring to be kept moist all season long, they are otherwise easy to grow and surprisingly reliable in most climates. All celery needs as much mild weather as can be provided. It's usually best to start seeds indoors up to 8 weeks before last frost of spring. The tiny seeds should be surface-sown and not covered, or covered only minimally, and kept uniformly moist until seedlings are strong. Then set out in the garden around last frost date. Thrives in fairly heavy, moist soil with lots of organic matter. Cutting-types and root-types are generally successful in the home garden.