How to Plant & Care for Leeks
Plant leeks in well-drained soil rich in organic matter. In clay soil areas, plant bulbs in a raised bed amended with humus. The soil should be consistently moist, but not waterlogged.
Leeks mature in 70-150 days but grow rapidly in cool weather. To increase the amount of white shank on the stalk, blanch the stems by mounding soil around them, or plant the leeks in the bottom of trenches, gradually filling in with soil as the stems grow. Weed around the plants frequently.
Use water-soluble plant food, or fish emulsion twice a month to feed the plants. In cool areas, dig plants and store in a cool location before the first frost date, or leave them in the garden with heavy mulch and harvest as needed. Dig any remaining leeks in spring.
Leek seeds will germinate best in soil temperatures from 70-75°F but can be sown a month before the last frost date. Seedlings started indoors can be transplanted around the last frost date and anytime up to a month before the first frost.
How to Harvest Leeks
Leeks can be pulled or dug any time after the shanks reach ½” or more in diameter. Make sure to thoroughly clean the root before preparing as soil can get inside the leek root.