This section is from the book "Vegetable Gardening", by Ralph L. Watts. Also available from Amazon: Vegetable Gardening.
This member of the onion family produces a sheaf of leaves (Figure 83) rather than a bulb. The sheaf is made up of the lower parts of the flat leaves, is solid and, when well blanched, milder and more tender than the onion. Leeks are generally eaten raw, but are also cooked and used for flavoring. This vegetable is much more popular in some foreign countries, as France, England, Scotland and in southern Europe, than in America, where it is.
Fig 83 Leek grown mainly for the foreign population.
Soil and cultural conditions required for onions are equally well adapted to leeks. Rotten stable manures are of great value. The usual plan is to sow in the spring as soon as the ground can be prepared. In June or more often in July the seedlings are transplanted in moist, well-prepared soil. It is an advantage to clip the tops severely at transplanting. The plants may be set 4 to 6 inches apart, with not less than 12 inches between rows. As the long, white sheaves are the most tender and salable, it is customary to plant the seedlings 4 or 5 inches deep in trenches which are gradually filled as the plants grow, or to set them slightly deeper than they stood in the seed bed and hill as the season advances in order to blanch the sheaves. They are also sold green to some extent. Leeks are readily stored like celery in trenches, cold frames, pits and cool cellars.
 
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