How do you blanch leeks before harvesting?

Online Answer
If you want really long, white stems, you can 'blanch' your leeks two to three weeks before you want to harvest them. Simply draw the soil up around the shanks to exclude light, or tie cardboard tubes around the stems.
Related Questions 📌
It is an essential step before freezing many vegetables including broccoli, leafy greens, string beans, okra, and asparagus. Vegetables that are frozen without having been blanched are safe to eat, but have "off" colors, textures and flavors.
Vegetables frozen without blanching are still safe to use, but there is a significant loss of quality, particularly if they're stored longer than a few months. An alternative choice is to boil the broccoli or cauliflower until barely fork-tender, then ice bathe them and freeze as described above..
Should you blanch broccoli before stir frying? Blanching broccoli is not necessary for stir frying, especially if you cut the florets small. If the florets are big they may take longer to cook in the wok, which may mean your chicken (or other veggies) gets overcooked.
Blanching stops enzyme actions which otherwise cause loss of flavor, color and texture. In addition, blanching removes some surface dirt and microorganisms, brightens color and helps slow vitamin losses. It also wilts greens and softens some vegetables (broccoli, asparagus) and makes them easier to pack..
It has a much higher vitamin and mineral content, containing considerable amounts of Vitamin C as well as calcium and iron. Also it's much easier to grow, doesn't require blanching for whiteness (the heads are purple when raw but turn emerald-green when cooked) and maintains its quality a long time after the harvest.Nov 14, 1987.