Cymbopogon flexuosus.

East Indian lemongrass, and the choice isn't incidental. There are two culinary lemongrasses: Cymbopogon citratus, called West Indian, the one sold as stalks in Asian groceries, and flexuosus, this one. The decisive difference for a gardener: citratus practically never produces viable seed and multiplies only by dividing the clump, whereas flexuosus can be sown. So it's the only one of the two you can start at home from a packet, and it's a little more vigorous and a little more tolerant of cool weather into the bargain. Grown in India for centuries, it's also distilled there for its essential oil, one of the world's great sources of citral.

A large grass in a dense clump 60 to 120 cm, with long narrow blue-green leaves with cutting edges (careful with bare hands), which release on crushing a bright, clean lemon perfume without the bitterness of zest. That perfume comes from citral, exactly the same molecule that scents lemon balm and lemon verbena, but far more concentrated here. In use, two distinct parts: the white fleshy base of the stalks, tender, which you crush with the flat of a knife and chop finely for Thai curry pastes, tom yum, Vietnamese marinades, Indonesian grilled chicken; and the long leaves, too fibrous to eat but perfect for infusion, fresh or dried, alone or with ginger, or thrown whole into a broth and removed before serving.

Grower's tip: it isn't hardy here. It's a tropical plant, and it doesn't survive a Québec winter in the ground, even protected. The strategy that works: a large pot, outside from June to September, brought in before the first frost to a bright room, cut back to 20 cm, watered very sparingly all winter. It starts up again in spring and grows larger year by year. For sowing: fine seeds laid on the surface without covering (they need light), sustained heat of 25 to 30 °C, slow and uneven germination of 10 to 21 days. Start 10 to 12 weeks before moving outdoors. At harvest, don't cut flush: take the outer stalks by twisting at the base — the clump restarts from the centre and produces all summer.

• Open-pollinated. Tropical perennial, not hardy in Québec: grow in a pot and overwinter indoors, or as an annual.
• Height: 60 to 120 cm in a dense clump.
• Maturity: 90 to 100 days. First usable stalks as soon as they reach the thickness of a finger.
• Exposure: full sun, warmth.
• Rich, well-drained soil, kept cool during active growth. Space plants 60 cm apart, or one plant per pot of at least 30 cm.
• Start indoors 10 to 12 weeks before moving outdoors, on the surface without covering, at 25-30 °C. Move out only once nights have stabilized above 12 °C.