Sow in pots or trays on a windowsill or in a greenhouse at approximately 15-18°C (55-65°F) using a good quality, moist compost. Do not exclude light. Cover with a polythene bag to retain moisture. After two weeks, place in a domestic refrigerator for a cool period removing when germination first occurs, usually 14-35 days. Place in good light and transfer when large enough to handle 5cm (2") apart in trays. Plant out 30cm (12") apart in autumn in a moist, semi-shaded position.