I've never tasted a leek before, but my daughter planted a bunch of leek seeds and they all came up so I did some research on how and when to separate the leeks.

Alien looking leek seedlings.

I was able to find some very useful information on growing leeks here.

Growing Leeks

Grace your dinner table with an easy-to-grow, elegant onion cousin: the leek. Sweet and mild, leeks are gentle on the digestive system and play the role of onion in dishes, only toned down. Unlike onions, leeks don’t produce bulbs, but stash their flavor in thick, juicy stems, looking similar to a giant scallion. Leafy stems are pretty and don’t need much room in the garden.

You will find a clump of several leek seedling plants in our pots.

In the supermarket, leeks cost a premium; harvested from the garden, their a trouble-free bargain. Leeks are most famous for leek and potato soup, but they’re also good steamed like asparagus, oven-roasted, chopped in quiche, or wrapped in ham, baked, and covered with cheese sauce.

Frost-tolerant leeks thrive in cool weather. In Zones 7 and warmer, plants can overwinter in the ground, perfect for fall planting. In northerly zones, tuck plants into beds in early spring, as soon as soil can be worked.

• Soil, Planting, and Care
• Troubleshooting
• Harvest and Storage
• FAQs

Even though our biodegradable pot directions indicate planting the whole pot, in the case of leeks, you need to remove the plant from the pot and very gently coax the clump of seedlings apart so that you can plant each leek seedling separately.

Plant leeks in a sunny spot in soil that is fertile and well drained. Leeks thrive in traditional garden beds, raised beds, or even in tall containers. Space leeks depending on the stem size you want to harvest. For thickest stems, space seedlings 6 to 8 inches apart. For thinner, scallion-size leeks, follow tighter spacing, setting seedlings 3 to 4 inches apart. You’ll gain the best of both worlds by spacing seedlings 3 to 4 inches apart and thinning every other stem when they reach scallion size, allowing remaining stems to grow to thicker size.

Leeks need two things to thrive: high nitrogen and consistent soil moisture. If possible, add compost or organic fertilizer to the leek bed the season prior to planting. Otherwise, work in organic matter into the ground a few days before if possible.

To produce a succulent white stem, leeks must be blanched—that is covered or hidden from the sun. To do this, plant leeks into deep holes. Deeper planting yields a more drought-resistant plant. Make narrow trench 6 to 8 inches deep and tuck seedlings into the trench, pulling soil up to the base of the first green leaf. Water well.

Bury the plants up to the point where the foliage arises from the stem, but not so deep that soil gets into the folds between the leaves.

After planting, mulch the bed with straw, grass clippings, or some other organic material to help soil retain moisture. Soak newly planted leeks with a liquid fertilizer such as Bonnie’s Herb and Vegetable Plant Food. Water leeks as needed until plants are established. After that, plants require an inch of water a week, either through rainfall or irrigation. Inconsistent moisture yields tough stems. Continue fertilizing plants with liquid fertilizer every week or so during the growing season.

As leeks grow, mound the soil from the trench around stems, beginning when stems are 1 inch thick.