Plant of the Week: Onion

Onion (Allium cepa)

Since we looked at garlic last week, I thought it would be a good time to learn a little more about it's close cousin the onion.

The common onion is probably the most widely used herb in the world and is used for culinary, medicinal and household purposes.  The onion belongs to the genus Allium like its cousins garlic and chives.  It commonly comes in three colors (white, yellow & red) and can have a strong pungent flavor or a mild 'sweet' flavor.  As a rule, the more pungent varieties have a longer storage life than their 'sweet' kin and are found year round in the supermarkets.  Until recently, the sweet varieties were found in stores only in the spring, but horticulture experts have developed 'new' varieties that are available at other times.  Many of those varieties are also available to home gardeners from mail order catalogs. :)

Onions require a long growing season and are most often planted from sets, small bulbs about the size of a dime in diameter, that are purchase from a garden center.  If you are looking for some of the more exotic and/or sweet varieties you will most likely have to start them yourself 8-12 weeks before your last spring frost or mail order them.  Plant your sets outdoors as soon as the weather will permit in well drained soil and full sun.  Prepare the soil by loosening the top 12 inches and mixing in 2-4 inches compost.  They should be spaced 4-6 inches apart.  Water them so that they get the equivalent of 1 inch of water a week but don't let them set in wet soil or they may rot.

Harvest onions when the tops naturally decline and fall over.  By this point, they should also have a papery brown/yellow skin around them.  After they are harvested, set them in the sun for a day or two to cure before storing them in a well ventilated, cool and dry location.

Happy Gardening! :)