Langford: Get the onions rolling

Saturday, April 14, 2007

Although spring weather varies from hot to cold and wet to dry, you can always start the garden off by planting onions.

This pungent bulb has a long, interesting history. Supposedly, it started as a cultivated crop in central Asia. Some reports place it on the banks of the Nile River as much as 5,000 years ago.

It has served as everything from a medicinal aid to a religious symbol and even as a boon to ancient Olympic athletes. In the 16th century, the onion was a touted cure for baldness; in Colonial America, onions were strung over doorways to absorb diseases.

Onions belong to the lily family. Their cousins are garlic, leeks, shallots, chives and even ornamental alliums that grow big, beautiful blue flowers.

Onions fall into the categories of fresh, pearl, green and storage. Fresh types, including Bermudas and Vidalias, keep for just a few weeks after harvest and are known for their great mild flavor. Storage types are usually thicker-skinned and have stronger flavor.

Onions come in white, yellow and shades of red. The bulbs can be round, flat or even torpedo-shaped. While they're usually grown from seed, the best approach this time of year is to use sets or transplants.

Sets are traditionally available from whites to reds and don't offer a wide variety. The small, dormant bulbs vary from a quarter-inch to an inch. Plant them 1 to 3 inches deep, depending on size. Place the sets a couple of inches apart, and as they sprout and develop, use the thinned ones for the table as green onions.

Transplants come in bundles as already-started plants 4 to 6 inches tall, with a fair number of varieties.

There's little danger from a late freeze with sets. Transplants could suffer some tip damage, but they'll recover. Put transplants 1 to 2 inches deep, depending on height, and an inch or two apart, depending on how many you want to pull early for table use. In either case, remember that these garden globes are shallow-rooted , so cultivate accordingly to avoid root or crown damage.

Irrigate the growing plants as needed, and plant them in a good, well-draining soil loosened with organic matter, such as peat or compost. For good results, work a commercial fertilizer, such as 5-10-5 or 10-20-10, into the soil before planting and add more at half-growth.

Harvest green onions when they reach about a foot in height, but you can thin for early enjoyment at the 6- to 8-inch stage. Full maturity comes in late summer or early fall, when the tops start to bend over. When about half of them have toppled, carefully step on the rest to bend them over and they'll continue to ripen.

Carefully dig or pull mature bulbs and let them cure for a couple of days. A good method is to braid the tops of several and hang the string over a low branch, where they'll have shade and air around them .

Finally, cut off the tops and store the bulbs in a mesh bag or openwork basket so the air movement can continue. Kept in a cool, dark place, storage types should last three months or longer.

Dale Langford is an area lawn and garden specialist.