Brassica oleracea var. gemmifera.

The Brussels sprout, despite its name, doesn't have much to do with the Belgian capital — at least no more than all the other variants of the extraordinary species Brassica oleracea it springs from. The plant was nonetheless cultivated on a large scale in the Brussels region from the 13th century, where shrewd market gardeners selected over the centuries this botanical curiosity: a tall straight stem along which forms, at the axil of each leaf, a small miniature head — a perfect mini-cabbage. The Long Island Improved variety, selected around 1890 in the market gardens of Long Island near New York by the Peter Henderson house, was long the North American standard and remains one of the rare open-pollinated varieties still widely grown in home gardens.

An imposing plant 50 to 60 cm tall, looking like a miniature palm whose trunk is studded with small tightly packed dark green balls — 50 to 100 per plant at full production. Each sprout 2 to 3 cm across, firm, dense, with a pronounced cabbage flavour and a sweet, nutty note that develops with the cold. Delicious roasted at high heat in the oven until the outer leaves caramelize (the new culinary religion that has rehabilitated this much-disliked vegetable), pan-fried in butter and bacon, steamed and drizzled with a maple-mustard vinaigrette, or simply halved and grilled on the BBQ. A precious peculiarity: it's one of the very rare vegetables you can harvest under snow — often into November or even December in Québec. The first hard frosts don't damage it, they improve it. Sugars accumulate in response to cold as natural antifreeze, and a Brussels sprout picked after a frost is on a completely different plane from one harvested before.

Grower's tip: Long season (90 to 100 days after transplanting), indoor start indispensable in Québec — early June for a late-October-to-December harvest. Like all crucifers, susceptible to the cabbage worm — insect netting mandatory from transplanting on. To favour the development and uniformity of the sprouts, many gardeners pinch the plant's terminal bud in mid-August (about 6 weeks before harvest) — this stops upward growth and redirects energy toward maturing the existing sprouts. Harvest from the bottom upward as the sprouts become firm and well-formed, ideally after one or two good frosts.

• Open-pollinated. Biennial — flowering only occurs in the second year. Insect-pollinated; crosses with all other Brassica oleracea (cabbage, broccoli, kale, etc.) — isolate rigorously for seed saving.
• Height: 50 to 60 cm.
• Maturity: 90 to 100 days after transplant.
• Exposure: full sun.
• Very rich, deep, well-drained, slightly alkaline soil (pH 6.5-7.5). Hungry plant — amend generously with mature compost. Space plants 60 cm apart in all directions.
• Indoor start 6 to 8 weeks before transplanting (early June in Québec). Tolerates and improves with hard frosts — harvest possible into November-December. Strict rotation with other crucifers.