Leeks Growing Guide

Leeks are hardy, mild ­flavored and a member of the onion family. Leeks are made up of sheaths of basal leaves rather than bulbs. Leeks can be eaten raw or cooked.

Site Characteristics

Light:  sunny
Soil: well­ drained loamy
pH: 6.2 to 6.8
Temperature: cool
Moisture: moist
„ requires medium to high fertility with 
Well-drained, soil, high in organic matter, neutral pH.  

Plant Traits

Planting: direct seed in fall or transplant late winter
Spacing: 4­-6 inches
Hardiness:  hardy biennial
Fertilizer: heavy feeder

Growing Information

How to plant:
Plant 10 to 15 seeds per foot directly in the garden in the fall. Thinning to 4 inches apart.
Leeks may also be started indoors in the same fashion as you would onion transplants.
Germination temperature: 75 F to 85 F
Days to emergence: 14 to 21 days
Seed can be saved 1-2 years. - Leek seed should be stored in cool, dry location.

Maintenance and care

Leeks will grow in any garden that can produce good onions. In the spring when the plants are growing strong, cultivate by drawing the soil up toward the leek plant. This blanches the edible portion. Blanching makes the leeks longer and whiter.  Leeks are known to be slow growers, requiring at least 120 days to reach 1 to 1 1/2 inches in diameter.
Do not bank the soil around the leeks for "blanching" until they are at least the size of a pencil. Early banking will cause the plant to rot and die.


Leeks can be harvested throughout the spring. To harvest, loosen the soil and pull out the plant. Cut the roots off and all but 2 inches of the leaves. Leeks can be dug before a hard freeze and stored in the refrigerator. Leeks can  also be mulched heavily with fresh straw to harvest whenever the ground is not frozen. Spring harvest is usually completed
by late April and early May, before the leeks have a chance to begin a second growth which sends up a seed-stalk.