Leek

Winter leek varieties (e.g. ‘Blaugrüner Winter’, ‘Siegfried’) you leave standing in the bed and harvest as needed through the winter; earth up the rows in autumn, which lengthens the white shanks and protects the root zone from freezing through. In severe frost or frost without snow cover, cover the bed with dry leaves, straw or brushwood and, if needed, additionally with horticultural fleece. Summer varieties are not hardy and must be harvested before the first frost.

You propagate leek almost exclusively by sowing. Start it indoors from February to March (summer leek) to May (winter leek) in seed trays at about 18 to 22 °C. Germination takes around 1 to 2 weeks. As soon as the young plants are pencil-thick (after 8 to 12 weeks), plant them outdoors in deep furrows (about 10 to 15 cm) with about 15 cm between plants. Planting in the furrow promotes the long white shank. If you want to save your own seed, let strong winter plants flower in the second year, because leek is biennial. For offspring true to type you need several plants of the same variety (about 10 to 20), since leek is cross-pollinated. F1 hybrids are not passed on true to type. A supplementary vegetative method is bulbils. If you cut off the flower head before it opens, the plant forms small daughter bulblets at the base of the flower or at the base of the mother plant. Dig these up in summer and replant them immediately; do not store them. Cuttings or division as with chives do not work with leek, because it forms no rootable shoots and no divisible clumps.