This wonderful tasty, hardy, attractive vegetable is easy to grow, won’t bolt (because it’s a biennial), and will provide an eye-catching change from winter roots at your market booth or CSA. Leeks have a mellow onion-like flavor with no pungency, and come to maturity when bulb onions may be long gone. Unlike onions, leeks will grow independently of day-length, and will stand in the field, at temperatures below what many other vegetables can handle, increasing in size until you choose to harvest them. This flexibility about harvesting date during fall and winter is a boon to growers wanting to provide a somewhat steady supply of produce. Planting dates can be chosen to suit your climate. Leeks are not just for leek and potato soup! Some recipes and cooking suggestions can be included for your customers.

Varieties
Leeks come in two main types: the less hardy, faster growing varieties, often with lighter green leaves, which are not winter-hardy north of zone 8, and the blue-green leafed hardier winter varieties. In the first category, we like Lincoln (50 days to slender bunching leeks, 75 days to mature leeks), King Richard (75 days, fast growing), and Giant Bulgarian. American Flag has not worked well for us. This year we are also trying Varna (50-85 days, slender and tall, often bunched). Giant Musselburgh (105 days) is bolt resistant, for those overwintering leeks in warm climates. For winter leeks we like Laura (115 days, extremely hardy, but no longer readily available), and Tadorna (100 days, almost as hardy as Laura). This year we are also trying King Sieg (84 days, a cross between King Richard and the winter-hardy Siegfried, from Fedco), Bleu de Solaize (105 days, reputed to be very hardy). Others include Winter Giant (Alaska) and St Victor.

Crop requirements
Leeks do best in well-draining soil rich in nutrients, with a pH of 6.5, and good sunlight. Ideal growing temperatures are 55-75 F. Growth is slow above 77F, but the plants do not deteriorate, and will resume growth when cooler weather arrives. Some varieties are hardy to 10F, or even below 0F if protected by a 12” mulch of straw or hay. Rowcovers could also be used.

Sowing
Leek seed keeps for only one more year after it’s sold, so don’t make false economies there. There are 10,000 seeds per ounce. Leeks will germinate between 52-73F, and depending where you live, there are several strategies. Leeks are slow growing, but easy to care for, and frost tolerant. Plan back from your expected first harvest date, using the days to maturity (7-17 weeks) in your calculation. Add 12 weeks from sowing to transplanting to these times, and 1-2 weeks for the seed to germinate. For most of us, this means sowing in January, February or early March. Seeds may be sown (1/4” – _” deep) in open flats, or channel trays at 3 or 4 seeds per inch, or in plug flats in clumps of 4 or 5. Seedlings in open flats may later be pricked out to 2” apart – this is probably more worthwhile for those with a short growing season. Harden off the seedlings before the transplant date.

If you have plenty of good growing season, as we do in zone 6b/7, you can delay sowing till March. We forego the indoor planting, for simplicity, and sow in an outdoor nursery bed on March 21. We sow _ – _” deep in rows 3” apart. We sow 10’ for every 100’ of  the final row at 6” spacing. As needed, the seedlings are thinned to _-1” apart, and weeded. Leeks do not compete well with weeds. We transplant ours in late May or early June, in beds cleared of early spring crops, or finished strawberries.

People with a long growing season (zones 8-9a) can plant two crops: the first 12-14 weeks before the last spring frost, and the second in mid July, to transplant in late September or early October. In zones 9b-11, sow only in July, and use a bolt resistant variety for leeks to harvest in the new year. If sowing in hot weather, chill the seed overnight before sowing, and keep the seedlings cool but brightly lit.

Transplanting
The ideal size for transplanting is between a pencil lead and a pencil in thickness. We plant at 6” spacing, with 4 rows to a 48” bed. People wanting really huge leeks use wider spacings. Leeks can also be planted in clumps of  4-6, either at 10-12” in-row spacing for easier hoeing, or at 6” for smaller bunching leeks. We use a special planting technique for our bare root transplants, in order to develop long white shanks, which are prized more than the equally edible green parts. A similar technique can be used for seedlings from flats, or plugs. We find it efficient to divide the crew up and specialize in one part of the job.

First, if the soil is dry, water it well, preferably more than an hour ahead. Then one person makes parallel V-shaped furrows, 3” deep, along the bed. Next, a couple of people make holes 6” apart in the furrows. Tools for this job include hoe handles, purpose-bought “dibbles” or dibblers, or ones homemade from broken digging fork handles, with the end sharpened to a point. The tool needs to have a diameter of  1 _-2”. The depth of the holes is determined by the height of the transplants. It’s likely to need to be 3” or more. If the holes cave in, you need to water the soil more before proceeding. Meanwhile another person digs up some of the transplants from the nursery bed and transfers them to a small bucket containing an inch or so of water. We make useful little buckets from 1 gallon plastic jugs with the top cut off. A rope handle knotted into holes at the top of the new bucket make it easy to carry. (A brief diversion: these buckets with longer rope handles can be carried around the neck and make great “two hands free” berry picking buckets). Resist any temptation to trim either the roots or the tops of the leeks.

To transplant, take a leek, shake it free from its neighbors, and decide whether to plant it. Do discard the ones thinner than pencil leads. If the plant is good size, and looks healthy, twirl it as you lower it into the hole. This works best if the roots are still wet and muddy from the water bucket. Avoid having the roots folded back on the plant, pointing at the sky. If necessary, explain to your crew why this won’t work. Bobbing the plant up and down as you settle it in the hole will help a transplant that has slightly bunched roots. If at first you don’t succeed, remove the plant from the hole, dip it back in the water and try again. Soon you will develop this quirky planting skill, and will be able to move along the row at a good clip. Ideally the tops of the leaves will poke out of the furrow, not more. Get the depth of the hole-making adjusted to suit the prevailing plant height. Don’t fill the holes with soil. Surprising as it may sound, it is not necessary or desirable to fill the holes. This usually happens naturally as the plants grow.

Next comes someone who gently waters each hole, either from a low pressure hose, watering can, or using an overhead sprinkler, once everyone else is out of range. The goal is to water the plant roots, adding only a little soil to each hole. The shelter of the hole helps the plant get over the transplant shock, and because leeks have slender tough leaves, they do not lose a lot of water by transpiration. This means that transplanting in quite hot weather is possible, as is transplanting in the mornings.

Keep the soil damp for several days after planting, and then give 1” water per week as needed. Like other alliums, leeks do not compete well with weeds, so cultivate as needed. Hoeing will help fill the holes. Some people hill up their leeks, but if you do, be careful not to get soil above the point where the leaves fan out from the stem, or they will be very hard to clean later.
If you have grown seedlings in plug flats or channel flats, you could instead transplant leeks in bunches of up to 6 leeks, with bunches 10-12” apart. This makes for easier weeding, and is fine for small leeks for early harvesting in late summer.

Harvest
Leeks can be harvested whenever the size seems big enough. Some people plant leeks in rows much closer together than we do, with the plan of harvesting out alternate rows in late summer, leaving every other row to grow to full size, possibly hilled up.

When harvesting leeks, remember how deep you planted them, and try to avoid spearing them. Put the tines of a digging fork (spading fork) vertically down in the ground 2 or 3” away from the leeks. I try to dig up 2 at once for efficiency. Step on the fork, lever back until the leeks move. Impatient pulling of unloosened leeks leads to broken ones. Remove one leek, chop off the roots, invert the plant and cut the leaves in a V shape, so that the tougher outer leaves are shortest, and the younger inner leaves are longest. Clean up any obviously inedible outer layers, then put the leek in a bucket. We like to put an inch of water in the bottom of the bucket before taking the leeks to the cooler.

If the ground is frozen too deep to pierce the crust with the fork, you may be able to harvest a few leeks by pouring boiling water along the row at the base of the plants. it does not seem to damage the leaves.

Storage
Leeks are best stored at 33F and 65% relative humidity. We use a walk-in cooler, and keep the root ends of the leeks in water. It is also possible to store leeks with the roots packed in soil, in a root cellar. They will keep for 2-6 weeks upright shoulder to shoulder in a crate or box. They can be stored in plastic bags for 2-3 months at the right temperature, or they can be stored frozen. Another possibility is to leave them in the garden, mulched with 12’ of straw or hay, and rowcover, if temperatures are below 10F. Our winter temperatures fluctuate a lot, so in-ground storage doesn’t work well for us.

Not Just Leek & Potato Soup!
Both the white and the green parts of the leek are delicious. Only the tougher parts of the outer leaves need to be composted. In general, leeks go very well with white sauces, cheese, mushrooms, pastrycrust and doughs. British recipe books often offer a lot of ideas.

Sources for Seed and Plants
Fedco Seeds, www.fedcoseeds.com/ Seeds of several varieties.

Johnny’s Selected Seeds, www.johnnyseeds.com/ Seeds of 5 varieties and King Richard plants.

Turtle Tree Seeds, Copake, NY  www.turtletreeseed.com/ Seed of 6 varieties

Gourmet Seed International www.gourmetseed.com/ 505-398-6111 Seed of 7 varieties.

Growing Information
Commercial Leek Production Guide for Oregon:http://hort-devel-nwrec.hort.oregonstate.edu/leek.html

Pam Dawling manages the vegetable gardens for Twin Oaks Community in central Virginia. The gardens supply the 100 residents with almost all of their fresh and processed vegetables.