How to Grow Leeks

comments (9) July 29th, 2008

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Leeks are easily started in soilless mix. When they reach the thickness of a pencil lead, they can be transplanted outdoors.
To maximize the white part of the leek, pile up soil around the plants as they grow.
To harvest, pull the leek up by the shank.
Leeks are easily started in soilless mix. When they reach the thickness of a pencil lead, they can be transplanted outdoors.Click To Enlarge

Leeks are easily started in soilless mix. When they reach the thickness of a pencil lead, they can be transplanted outdoors.

Photo: André Baranowski

A few years ago, when I was living in Scotland, I often wandered the quaint streets of Musselburgh, a village clinging to the fringes of Edinburgh. I especially admired a stone cottage with a pretty border of leafy, blue leeks lining the paving stones from street to front door. In every back garden I glimpsed, leeks grew. Between hills of potatoes, in circles around the tomatoes, tucked among the salad greens were leeks, leeks, leeks.

Imagine my joy when, seed shopping for my own tiny garden, I saw a packet of ‘Musselburgh’ leek seeds. I planted them that year, and have been saving seeds for this succulent variety ever since. I brought those seeds across the Atlantic with me, only to discover the variety is available here. Some catalogs in this country call it ‘Giant Musselburgh’ and with good reason.

The leek is not only a beloved vegetable and garden ornament, but also the Welsh national symbol. As such, an image of a leek is imprinted on the British pound coin every third year. Britain isn’t the only country with a passion for leeks. In Prague, I’ve watched shoppers clamor to buy onions, which are expensive and scarce. Plain old leeks can be had for a pittance any time. In Europe, everyone grows leeks. They are eaten daily, and are available in markets from Aberystwyth to Athens at low cost.

In this country, we pay about a dollar apiece for leeks, but it’s easy to grow your own. Using methods I’ve developed over several years in Edinburgh and in Connecticut, I enjoy an ample supply from late summer through spring.

A leek for every season

  Leek culture
• Sow leeks indoors in late winter for fall harvest. Start more leeks in August for spring harvest.
• Grow them in soil that has plenty of compost and nitrogen.
• Don’t let leeks lack for water.
• Once leeks start growing, hill them up every 2 weeks to get more of the white part.

Leeks are a biennial member of the alliums, a tribe that includes onions, garlic, shallots, and chives. The white shank has a mild, almost sweet, onion flavor; the green tops are stronger tasting. I grow several varieties, sowing a spring crop to eat late summer into winter, and a fall crop to enjoy in the spring.

Leeks grow superbly in cool, rainy places. They don’t mind warmer, drier climates, though, when pampered with lots of water and thick layers of mulch to keep the soil cool and the weeds at bay.

In southern New England, I sow leeks indoors in March. The relatively quick-growing ‘Falltime’ goes in the ground mid-April and is ready to eat by August. ‘Kilima’, also started in March, matures in early fall. ‘St. Victor’, which turns a lovely soft purple in cold weather, is ready for holiday soups and stews. The color fades in long cooking, unfortunately, but the magnificent display in the garden is reason enough for growing ‘St. Victor’.

I start more ‘Falltime’ seeds at four-week intervals over the next two months. Started as late as May, ‘Falltime’ will give me leeks for Thanksgiving if I fertilize them well. Leeks are heavy feeders. Mine get a weekly gulp of compost- or manure-tea throughout the growing season. Lots of nitrogen makes for large, succulent leeks.

‘Giant Musselburgh’ really makes my most superb crop of leeks. Long in the shank, firm, and a good choice for overwintering, ‘Musselburgh’ has acclimated itself to my garden, getting bigger and hardier every season.

‘Scotland Heirloom’ isn’t just a pretty face with its blue color, but also a very hardy, short-shanked leek with what I consider the very best texture and superlative taste. I sow this variety in March and again in August. It too overwinters very well.

For spring leeks, sow in late summer
For leeks to overwinter, I plant seeds in flats in August, sowing thinly to avoid transplanting before setting out. If you live in warmer climes than New England’s, you can start them through the end of September.

I start my seeds in soilless mix: equal parts perlite, peat moss, and sifted compost, with a handful of sand. I mix up a big plastic garbage can of the stuff, blending about 1 gallon of sand for every 8 of combined perlite, peat moss, and compost.

I leave August-sown seeds outside, protected from noonday sun. Then, about two weeks before setting out, I supplement their water with manure tea or fish emulsion twice weekly. Leeks are ready to be set out when they’re about the thickness of household string or a pencil lead.

Hill the leeks
  As the leeks grow, hill them up. Pile an inch or so around each plant every few weeks to blanch the shaft.

Before planting, I double dig my beds. I mix the topsoil with compost plus a little sand for good drainage before placing it back in the bed. If this sounds like too much work, simply spread compost, leaf mold, or other organic matter on top of the garden and lightly fork it in. If accommodated in their predilection for fertile soil and ample water, leeks will reward you with bigger shanks, better texture, and sweeter flavor.

I plant leeks in trenches 6 in. deep. As they grow, I hill them up, piling an inch or two of soil around each plant or along the row every couple of weeks. Hiding the shank from light blanches it, producing more of the tender white part.

Watering well is important. I soak my beds twice a week. Leeks that suffer from lack of moisture grow unevenly, and have a stronger taste and pithier texture.

To overwinter leeks, I make sure to get them in the ground before frost. Then I bury them completely with straw or old, dry grass clippings. The first really cold night, I cover the whole bed with an old sheet. Early in spring, I remove the sheet, replacing it when nighttime temperatures plunge below 30°F. When the weather warms, I remove the mulch. I’ve had small but usable leeks as early as April.

Leave some leeks in the garden to set seed.
The second year, each grows a lovely starburst cluster of tiny whitish flowers on a long and delicately twisted stem. Once the florets are all open, it is three to four weeks before the tiny black seeds mature.
Leed seedhead, opening Leek seedhead, open

To harvest, dig and pull

  Harvest the leeks
  To harvest, pull the leeks up by the shank, and shake off the excess soil.
Store harvested leeks
  Store leeks in a cool, dark spot. Place them horizontally in a box between layers of damp sand.

Leeks are ready to harvest when they’re large, firm, and not too bulbous at the base. A 1-in.-diameter shank is a good size for most varieties. Loosen the soil with a garden fork, lifting up the leeks. Grasp the shank and pull, then shake the leek to free it of excess soil. Rinsing with a garden hose is a good idea. Leeks hold lots of dirt.

At that time, I pick one or two stalks and put them upside down in a brown paper bag. I tie string round the neck of the bag and hang it in a cool, well-ventilated spot for about a month. Then, working over a bowl, I shake and rub the flower heads between my fingers to loosen all the seeds. I pick out the seeds from the debris and store them in empty film canisters.

In the late winter, I still have some of the leeks I harvested the previous autumn; my favorite for their keeping qualities are ‘Tenor’ and ‘Alaska’, which can be difficult to locate, as varieties offered in seed catalogs vary from year to year. I store only perfect leeks, in a dark, very cool cupboard in a dry, well-ventilated room. I fill boxes with an inch of damp sand, then a horizontal layer of leeks, more sand, a layer of leeks and so on. I do trim some of the tops off very long leeks, but, except for a thorough rinsing (with enough time to dry), I prefer to store leeks much as they are when they come from the garden.

Tasty leek recipes:

Braised Artichokes with Leeks and Peas
Andrea's Vegetable Menestra
Leek and Potato Soup
Leeks Braised in Red Wine
Peasant Soup






by Abigail Wiscombe
October 1997
from issue #11

posted in: leeks

Comments (9)

carlbeckt writes: Very nice.
Posted: 1:24 am on June 3rd
marcpatton5 writes: Really effective
Posted: 2:28 am on March 25th
RebeccaWeber writes: This is really helpful for me:)
Posted: 4:39 am on February 24th
MarrieRass writes: Truly wonderful article!
Posted: 4:02 am on February 23rd
Charlie_Tea writes: Great article! Last year I planted leeks for the first time (King Richard) I made the mistake of not planting them deeply enough or not mounding soil around the leeks as they grew; so the crop was not a huge success. I live in Northern Virginia and plant some of my vegetables as "edible landscape." This year I bought musselburgh leek seeds and am going to try again using some of the information I learned from this article. I am going to plant the seeds indoors at the end of February and transplant them outside about April 1. Our average last frost is April 15-20; so I may cover them with newspaper if we get a frost. I have a raised garden bed 5' x 18'. I will plant the leeks down the middle of the bed in a row and plant a row of beets on one side and a row of bright-light chards on the other side. To make planting easier and more uniform I wanted to make a template to use to make the holes for the leeks. I am going to use a 12" X 12" piece of 1/2" plywood, attach a screendoor handle to one side and attach 1/2" diameter dowels, 4" long spaced 6" apart on the other side of the plywood. Is 4" long enough for the planting holes?
Posted: 8:32 am on January 29th
pattij writes: What do I do with the leeks after they flower?
Posted: 10:14 am on July 15th
Downsizing writes: I always grew leeks before "downsizing" & found that, with care, one could gently pull a plant until the top of the root was just below soil level, then cut it off with a sharp knife and firm the root back into the soil. The leek then regenerates, tho it will be smaller than the first cutting.
Corinne (South Africa)
Posted: 11:37 am on June 14th
Ruth writes: Leeks are a great addition to any garden. If you let them winter over and don't harvest them in the spring, they will. form a flower head and go to seed. The seeds will fall to the ground, and soon you'll have new seedlings, which can be transplanted out after they grow a bit. So the crop can be self-renewing.
Posted: 8:55 am on September 17th
JadaE writes: Extremely helpful article! I bought a packet of "Giant Musselburgh" on a whim (ever buy seeds on a whim?), but now I'm excited to get my seeds started tonight!
Leek and potato soup in my future..... :)
Posted: 2:31 pm on September 14th
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