Sow directly outdoors when the soil is firm or in early autumn. Water the soil before sowing and keep moist during the germination period. Groningen can be accelerated by soaking for a day before sowing. Overwintered plants give a fine spring harvest. Can also be pre-cultivated indoors in March-April. Transparent cover with air holes, or aerate regularly. Plant out after hardening off in May-June. Harvest gradually throughout the summer. Blooms the second year and should therefore be sown annually for good availability.
