They require about 120 days from seed to maturity. The edible portion of the leek stem should be blanched for best flavor and tenderness. When the plants are at least the width of a pencil, begin to gradually draw soil up around the base of the plant to blanch the lower stem. Avoid starting to blanch the stems too early. Otherwise, grow as you would onions.
Leeks are subject to the same problems as are onions.
The variety Arkansas is recommended for growing in South Carolina. This very productive variety has good disease resistance. Leeks are ready for harvest when they are an inch or more in diameter. Leeks will keep for several weeks in a refrigerator. They have a mild, delicate but distinctive flavor and can either be grown for use as green onions, or for the clusters of small bulbs that are used like garlic or onions.