Romanesco

Romanesco is an uncommon, eye-catching cultivar of Brassica oleracea that dates back to the 16th century. It was once grown only around Rome and makes light green heads of cone-shaped florets arranged in spirals. Although it is called romanesco broccoli or Roman cauliflower, it is neither one. The plants look much like broccoli or cauliflower in the garden, and heads can reach up to 5 pounds (2.3 kg).

The flavor is mild and often described as nutty and slightly spicy, with a texture like cauliflower.

Sowing. Although romanesco is a cool-season plant, it does best when started indoors 4 to 6 weeks ahead and transplanted into the garden after the last frost. It is usually found at farmers’ markets or grown from seed.

Spacing and site. Plant seedlings 18 to 24 inches (46 to 61 cm) apart in fertile, well-drained soil. Choose a spot with full sun, meaning 6 or more hours of direct sunlight a day.

Watering and feeding. Keep plants well watered and fertilize once or twice during the growing season.

Romanesco gets the same insect and disease problems as other brassicas, especially cabbage caterpillars such as imported cabbageworm, diamondback moth and cabbage looper. Floating row cover keeps adult moths from laying eggs on the leaves, though it gets harder to use once plants are large. Bt sprays or insecticides labeled for cole crops are other options.

Heads are ready about 75 to 100 days after transplanting. Cut the whole head with a sharp knife, or remove individual stalks, and choose dense heads with no discoloration. After the head is cut, the plant does not usually produce new side shoots.

Open-pollinated heirloom types vary a lot in head size and ripening time. Newer varieties are more compact, with more uniform and usually smaller heads and more predictable maturity.

Harvested heads keep for about a week in a plastic bag in the refrigerator.