Easy but start early to get good sized roots and keep moist. Sow under glass at 16 degree celsius in February or March in seed trays or modules (can be sown in a cold frame in March/April but will not get so large). Prick off into individual pots or thin modules to single seedlings. Gradually harden off before planting out in May in rows 30-35cm apart each way. Remove some outer leaves in July to expose the crown.