How to grow Collard Greens plants with celery seeds

Sow celery thinly in pots or boxes in heat in March for early varieties, or in a cold house in mid-April for the main crop. Prick off into deep seed boxes as soon as the seedlings are large enough to handle, at 5cm (2in) intervals. After hardening off, plant out from mid May to the end of June, in prepared […]