Only from pricked, vigorous young plants can be expected to develop well.
Growing celery is not easy. Sow early to mid-March in hand boxes or seed trays, either in the warm cold frame or in a bright room by the window 18 up to 20°C. The seed rate is only 0.3g/m2. From sowing to emergence often pass 3 weeks. As soon as the first leaf has formed, the little plants are pricked out again in hand boxes or straight into the cold frame at a distance of 5cm x 5cm. At first there is little ventilation. At latest 10 Days before planting, hardening must begin.