Leeks are a mild-flavored member of the onion family. Their tender, white stems are used to flavor soups, stews, meats and many different dishes. Although the green portions of leeks can be eaten, too, it’s the succulent white stalks that are prized; the green parts have a stronger flavor and a coarser texture. The greater amount of white on a leek’s stem, the more useful it is in the kitchen.
The white portion of a leek’s stalk is created by blanching, a process that protects that portion of the stem from sunlight. Many gardeners mound soil up around growing leeks to keep sunlight from reaching the stems, but this means soil gets in between the layers of the leek, and if not properly washed, you might get a mouthful of grit.
Instead of mounding my leeks, I use several recycled household items to blanch the stems. I begin the process about two months before I harvest, and it works like a charm.
To blanch leeks with newspaper, gather the leaves together and wrap the lower portion of the stem with newspapers. I use a thickness of about five sheets and wrap them around the stem twice. Then I secure it with a piece of jute twine or masking tape. Leave some slack in the newspaper so the leek can continue to grow but not so much that it lets in light. Yes, the newspapers get wet, but they’ll be intact when you’re ready to harvest a month or two later.
2. Empty Paper-Towel Rolls
For this method, I slice a paper towel tube open lengthwise and cut the height to match the lower portion of the leek stem. I fold the leaves upwards, slide the cut tube around the leek stem, and secure it with a piece of jute twine or masking tape. I leave the paper towel tube a little loose so the leek can grow a little but it still blocks the light.
3. Paper Egg-Carton Lids
While we use most of our egg cartons to gather more eggs, we always end up with extras. The bottoms are used as seed-starting trays, but until I discovered this trick, the lids were often discarded. To use egg carton lids to blanch leeks, cut the lid to the length of the leek stem.
Then cut a V into the curved edge of the lid, right where it wrap around the leek. Fold the paper egg carton lid around the leek stem, and secure it with a piece of string. The egg carton lid shouldn’t be too tight, but fatter leeks may need two carton lids to go all the way around.
4. Milk & OJ Cartons
This is a great way to blanch leeks, but it does require a bit more effort than the other methods. Cut the top and bottom off the carton and slide it down over the leek. You can put the carton over the young plant at the time of planting if you want, or you can wait to do it until a few weeks before harvest. If you put the carton over immature leek plants, gradually fill the carton with compost, sand, soil or shredded leaves as the young plant grows over the course of several weeks. If you put the carton around a more mature leek, fill it to the top all at once and allow it to stay in place for four to eight weeks before harvest.