Calabrese Growing Guide
A popular crop producing large, domed green heads (about 15cm across) of tightly packed flower buds, typically harvested from mid-summer to mid-autumn. Plants grow up to 60cm tall and wide. It is a versatile and nutritious vegetable, rich in vitamins and antioxidants, best enjoyed freshly picked.
This guidance applies to the crop in general. Individual varieties and local conditions can differ.
Planting information
Seeds are typically sown between March and June. For indoor sowing (March-April), sow 2 seeds per module, 2cm deep, in peat-free seed compost in modular trays, thinning to one seedling per module. For outdoor sowing (April-June), make a shallow drill 2cm deep. In a seedbed, sow thinly 7.5cm apart. For direct sowing in the final position, sow 3 seeds every 30-45cm along the drill and thin to one plant per cluster. Rows should be spaced at least 45cm apart. Small batches can be sown a few weeks apart for continuous harvest. Autumn sowing under cover in an unheated greenhouse is possible for spring crops. Transplant young plants when 10-15cm tall, ideally before hot weather. Harden off indoor-sown plants. Plant deeper than previously grown, with lowest leaves at soil level, firming in well. Space plants 30cm apart (45cm for larger varieties), with 45cm between rows. Water generously before and after transplanting.
Harvesting information
Harvest from mid-summer to mid-autumn, typically 3-4 months after sowing, when the main head is 10-15cm across, well-formed, and still in tight bud before flowers open. Harvest promptly. After cutting the main head, smaller side-shoots will develop; harvest these regularly for up to 8 weeks. Young, tender leaves are also edible.