Romanesco

Romanesco is a visually striking brassica that forms tightly spiralled, lime-green fractal heads with a flavour closer to cauliflower than broccoli — nuttier and milder than either. It is a cool-season crop that performs best where temperatures are moderate and steady, and it dislikes both hard frost and summer heat during head formation. Plants are vigorous and upright, demanding fertile, moisture-retentive soil and full sun.

Growing

Start seeds indoors at a soil temperature of at least 7 °C, sowing 0.5 cm deep, and expect germination in 5–10 days. Grow seedlings for about 6 weeks until sturdy before transplanting outdoors once nights consistently stay above 4 °C. Space plants 50 cm apart in all directions in fertile, well-drained ground or a raised bed. Direct sowing outdoors is possible once soil reaches 7 °C, but indoor starting gives more reliable heads.

Care

Keep soil evenly moist throughout growth — inconsistent watering causes loose or aborted heads. Apply a balanced fertiliser at transplanting and a nitrogen-rich feed once plants are established. Hoe shallowly around plants to suppress weeds without disturbing the shallow roots. Protect young transplants from cabbage root fly with fine mesh collars at the base of each stem.

Harvest

Cut heads when the spiralled florets are tight and bright green, before any yellowing or separation begins. A sharp knife at the base of the main head triggers smaller side shoots on some varieties. Harvest promptly — heads that pass peak can open and lose texture within days. The head is ready when it feels firm and dense to the touch.

In the kitchen

Use romanesco raw in salads or on crudité platters to showcase its fractal geometry. Steam or roast florets until just tender — roasting at high heat caramelises the surface and intensifies the nutty flavour. It works well in pasta dishes with anchovy, capers, and olive oil, or folded into a gratin. Blanch briefly before adding to stir-fries to preserve colour.

Storing

Store unwashed heads in a perforated bag in the refrigerator crisper for up to 5 days. For longer storage, blanch florets for 3 minutes, chill in ice water, drain, and freeze in a single layer before bagging — keeps well for up to 12 months. Do not store at room temperature as the head deteriorates rapidly.