Leeks (Allium porum) are related to onions but they don’t form distinct bulbs. Grow to 2–3 ft. tall, with an edible, mild-flavored stem that resembles a long, fat, green onion. Eaten by itself or in soups. Excellent varieties include ‘Giant Musselburgh’, ‘Lancelot’, ‘Lincoln’, and ‘Shelton’.
Performs best in cool-summer climates, but also does well in hotter areas if given some shade. Give very rich soil.
In cold-winter regions, set out transplants in early spring, or direct sow seeds in late summer for harvest the following year. In mild-winter areas, set out transplants in fall. Sow seeds indoors 1/2 in. deep, 1 in. apart, 8 weeks prior to planting date. Space seedlings 2–4 in. apart in a 5-in.-deep furrow. As plants grow, mound soil around stalks to blanch them (this makes the stem bottoms white and mild), keeping mounded soil just below the leaf joints.
Harvest when stems are 1/2–2 in. thick, usually about 4 to 7 months after setting out plants. In cold-winter climates, harvest before the ground freezes. (Where the ground doesn’t freeze, you can leave leeks in place and harvest as needed.) Lift out with a spading fork. Any offsets may be detached and replanted. If leeks bloom, small bulbils may appear in flower clusters; plant these for later harvest. To prepare leeks for cooking, slice off the roots and all but 2–3 in. of the green leaves; rinse thoroughly, separating the layers. Leeks are not bothered by many of the pests and diseases that attack onions.
Andean native, botanically known as Solanum tuberosum. For ornamental relatives, see Sola...
Annual. The wild ancestor of today’s familiar sunflowers, native to much of the central U.S. and...
Two kinds of mustard are popular in American gardens, both derived from plants native to the Mediterra...