Joe Lamp'l discusses the properties of green onions and how they differ from bulbing onions. These tender types of onions are edible from top to bottom, and they're a gardener's dream because they're very simple to grow.
Here are some basic facts about leeks, scallions and chives:
- Members of the onion family, they are often called green onions because you eat the green stems, not just the white base. All three of these are nonbulbing, which means that the bottoms get only as wide as the stems. Bulbing onions put all their energy and growth into the bulb below the ground; the onion produces sugar, fiber and starch, and that's what fills out the bulb and concentrates the flavor. Leeks, scallions and chives distribute their flavor and nutrients through the green stem. Since they have less sugar and starch than bulb onions, they are a very good low-calorie food.
- They are nonbulbing onions that like fertile, loose soil and lots of sun but not too much heat. When you're deciding where to plant them, choose a site that gets sun for most of the day, but not someplace where they'll burn up. A little morning or afternoon shade will keep onions from bolting, or flowering too soon, especially if you live in a hot climate. Some onions do better where the days are shorter and cooler; others can handle the heat of long summer days. Check with your extension service to see what onions will grow in your region.
- They need rich, moist soil. They grow much faster if the roots can take hold quickly and the stem can thicken without the pressure of heavy soil around it. Choose a bed that has good soil since the plants could be there for six months to a year.
To make the bed more fertile, add several bags of manure and lots of compost. Loaded with nutrients, both are a natural way to enrich the soil. Because both compost and manure are organic, they release nutrients slowly over the full growing season. This will give the leeks a steady supply of food that's easily absorbed by the plants. Strong plants are better at fighting disease and pest problems. Add a little dried bonemeal to get onion roots stimulated quicker. Once the roots get going, they have a better chance of success because they can take in food and water more quickly.
- Like all onions, they are part of the lily family, but they're different from other onions in a variety of ways. Because they have green leafy tops that are full of flavor and nutrition, you can eat the stems. They also grow, and are harvested, much more quickly than many other onions. This is what makes growing leeks, scallions and chives fun for kids and grownups: you can see what you're eating without waiting to dig them up.
To space seedlings properly you can use a planting board. Leek seedlings called Lancelot are available from a mail-order catalog. The catalog ships them from February to May, so be sure to place your order in time to receive them. These leeks come in bundles of 50 to 75 seedlings. You can't get all varieties of leeks in seedlings, so call around to local garden centers to see what's available in your area. You may have to order seeds to have a good variety of leeks in your garden; just check the description before you order to make sure it will grow in your zone.
- Leeks are biennials; that is, they have a two-year life cycle. Leeks germinate and mature over one season and then flower and produce seeds the following season. You normally plant leeks in the spring; in mild climates you can get a second crop by planting again in August. Leeks can be picked at any time; it depends on how large you like them to be when you eat them. To pick leeks at full maturity and before they flower, you should harvest them in fall (in colder climates) or winter (in warmer climates).
- If you're planning on thinning the rows as the leeks grow, double the number of plants. If you like to eat baby leeks in salads, plant two or three times what the row holds, putting a seedling every 3". If you do this, you have to remember to keep thinning them before the leeks start getting crowded. They should end up with 6" to 8" between plants by the time they mature.
- When all the leek seedlings have been planted, lightly tamp the soil with your hands. Mulch around the plants with wheat straw to keep them moist and cool until they can get started. Water the plants well to keep the small roots from drying out. It's especially important to water seedlings right after planting because dry garden soil can wick moisture from them.