By: Susan Littlefield
Begin harvesting leeks as soon as they are big enough to use; the slender young stalks are tasty braised. But for the biggest stalks, let short-season leeks grow until just before the first fall frosts. Be sure to loosen the soil around the leeks with a garden fork before pulling them up so they don't break off. Let the hardy long-season leeks remain in the garden until just before the ground freezes or throughout the winter in southern gardens. Mulching around the plants in fall with straw can extend your harvest season by keeping the soil from freezing. You can also harvest overwintered leeks in early spring before these biennial plants send up a flower stalk; after that, they'll be stringy and tough.
Harvested leeks will keep wrapped in plastic in the refrigerator for up to 2 weeks; cut off all but a few inches of the green tops to make them easier to store.