Propagate by
seed
Germination temperature: 45 F to 95 F
- Peak germination around 77 F.
Days to emergence: 5 to 7
Seed can be saved 3 years.
Choose a weed-free, well-drained location. Raised beds are ideal. Leeks
are good for intercropping with other garden plants, especially
early-maturing spring greens. Do not plant where other onion family
crops have been grown in the past 3 years.You can direct-seed leeks, or start transplants indoors. Long-season varieties are best started indoors.
Start
transplants about 8 to 10 weeks before last frost date. Sow seeds in
flats about ¼ inch apart and ½ inch deep. Transplant to cell-type
containers when they are about 2 inches tall. If you skip this step and
continue growing in open flats, simply tease apart and trim roots when
transplanting into the garden.
Around the average last day of
frost, set hardened-off transplants 4 to 8 inches deep, 4 to 6 inches
apart, in rows 20 inches apart. Deep planting reduces need for hilling
to blanch the base of the plants. Transplants should be about 6 to 12
inches tall - the bigger, the better. Only a few inches of leaf need to
show above the soil.
Direct seed about 4 weeks before average
last frost ½ inch deep, 1 inch apart, in rows 20 inches apart. Thin to
4 to 6 inches apart.
Hill or mound soil around stems several
times to blanch as leeks grow. (A single large hilling while plants are
young can cause them to rot.) Or, place a portion of cardboard paper
towel center around the lower part of the stem.
Leeks have
shallow root systems and need consistent moisture and good weed
control. Water weekly if weather is dry, and mulch to retain moisture
and suppress weeds.