Allium cepa.

An heirloom variety cultivated since at least 1873, native to Southport, Connecticut, and long considered the reference "white globe" throughout the American Northeast. It's technically an onion with a perfectly round pearly-white bulb, but its mildness in youth has made it for generations a favourite for the double harvest — picked young and slim all summer as a green onion (the first tender leaves and tiny bulb, chopped onto an omelette or in a vinaigrette), or left to mature through the full cycle to yield a full-sized bulb for winter storage.

It's a long-day onion — it needs 14 hours or more of daily light to trigger bulb formation, which makes it perfectly suited to northern latitudes like ours, where the short-day varieties sold further south would simply refuse to form a head worthy of the name. Mild, sweet flavour at fresh harvest, more pronounced after a few months of storage; sliced raw in a sandwich, melted into a classic onion soup, Russian-style pickled in jars with beet, or simply caramelized in butter as a garnish on a steak. Good keeper in the root cellar or cold room for 4 to 6 months if you take care to dry it well after harvest.

Grower's tip: Onion starts slowly and wants a long cycle. For a full bulb harvest in Québec (100 to 110 days), indoor start 10 to 12 weeks before planting out, at the rate of 6 to 8 seedlings per cell (yes, together — separate at transplanting, and a thin to 8 cm gives bulbs of good size). For green-onion harvest only, direct-sow as soon as the soil can be worked, in dense rows, and pick continuously as soon as stems reach 15-20 cm. For storage bulbs, stop watering when the tops start to flop, let dry in the field for a week, then braid or hang in a dry cool place.

• Open-pollinated. Heirloom variety. Biennial — flowering only occurs in the second year. Insect-pollinated; crosses with other Allium cepa nearby — isolate for seed saving.
• Height: 30 to 50 cm for the tops.
• Maturity: 30 to 40 days for green-onion harvest, 100 to 110 days for full bulbs.
• Exposure: full sun.
• Loose, rich, well-drained, stone-free soil. Thin to 3-5 cm for green onions, to 8-10 cm for bulbs.
• Indoor start 10 to 12 weeks before last frost for bulbs (late February in Québec), or direct-sow as soon as the soil can be worked for green-onion harvest.