Onions, shallots, garlic and leeks are all in the same genus of Allium and have much in common. Onions are the most popular of these crops in the United States, but in Louisiana, garlic and shallots are just as popular as onions. Alliums are quite hardy and grow from fall to late spring. Although the alliums are used mostly as seasonings, they are a good source of vitamin B.
Onions - Allium cepa
Onions may be grown for either bulbs or green tops (scallions). Planting from seed can start in late September in north Louisiana and extends through mid-October in south Louisiana. Plant onion sets or transplants mid-December through late-January.
Select “short day” varieties of bulbing onions. This is very important, since bulb formation is controlled by day length and temperatures. Bulb initiation begins in the spring as days begin to get longer and the temperature rises. Bulb size depends on variety and growing conditions. If a large bulb is desired, choose a variety capable of producing a large bulb, and that develops a large, vigorous plant before bulbing begins. Bulb shape depends on variety, depth of planting and soil type. Heavier soils and shallow setting produce a more flattened bulb. Crowding plants will also produce smaller and slimmer bulbs. Onions, particularly those grown for bulbs, produce best in light silty or sandy soils. Clay soils may interfere with the swelling of the bulb. Adding organic matter or compost to heavy soils can make good production possible.
Several good “short day” varieties are available for Louisiana conditions.
For red onions, the Red Creole and Creole C5 are popular selections. These are medium-small, pungent and store well. Red Burgundy, Red Grano and Tropicana produce a medium, mild bulb.
For white onions, Crystal White Wax is popular. It is a medium-size, mild Bermuda type also used for bunching onions. White Granex, Contessa, Eclipse and Early Supreme are also very good.
Yellow onions offer the most choices. Granex 33, Century, Georgia Boy, Miss Megan, Mr. Buck, Nirvana, Sweet Caroline, Sweet Vidalia, Texas Grano 1015Y and Texas Grano 502 are good choices.
Onions grown for green onions (scallions) or bunching onion grow well in all soil types. These onions are normally direct-seeded thickly in the row and are grown to suitable size and then harvested for table use. Varieties for green onion use include Crystal White Wax and the Japanese Bunching or “Nebuka” types, such as Evergreen Bunching and White Spear.
Leeks - Allium porrum
Leeks are alliums that are similar to green onions but milder in flavor. Leeks are grown from seed or small bulbs and planted in the fall. Although the above-ground portion resembles a thick-necked garlic plant, the thick white neck is used in soups, stews and for general onion use. Most varieties should be suitable for Louisiana home gardens.
Garlic - Allium sativum
Garlic is often toted as having many uses from warding off cancer to protection from evil. Louisianans use it to flavor food and boil shellfish. Varieties differ in size and pungency. The large bulb Tahiti, or Elephant, variety produces large darker cloves on vigorous plants. These cloves are mild in flavor. The Creole variety clove is smaller. Its pungency is moderate, and it does not store for long periods. Italian types have the strongest flavor and store best. Italian-type cloves are small and have pinkish skin. Home gardeners will do well planting many garlic varieties just be sure to select “soft neck type” garlic, which grows better in Louisiana than hard neck types.
When you buy garlic to plant, choose whole bulbs. Break apart the cloves just before planting. Planting a true clove in mid- to late fall should provide a plant that produces a cloving bulb in spring. Some bulbs will produce offset corms, which will grow up against the lower side of the bulb. These tough nutlike corms will produce a plant that develops a solid or non-cloving bulb of garlic resembling an onion bulb. These solid bulbs may be used for cooking. If replanted, the solid bulbs will produce plants that will clove the next year.
Shallots - Allium ascalonicum
Shallots are a key ingredient in many Cajun dishes. Shallots are similar to multiplying onions but have a garlic flavor. In Louisiana, green shoots are used as a green onion or scallion substitute. Varieties of shallots commonly found in Louisiana include:
Bonheur – medium size, some resistance to pink root, produces good dry sets.
Delta Giant – large and vigorous, some resistance to leaf spot and pink root, can be planted earlier and grows longer into summer before bulbing.
Summergreen – large, some pink root resistance, remains green year round and produces true seed in flower heads. May be increased by true seed or by dividing and separating.
Louisiana Evergreen – large, pink root resistance, remains green year-round and is increased by dividing and separating.
Because of mass trade and renaming of shallot varieties, finding a shallot with a variety name that is verifiable is extremely hard. Do not worry about the variety, just plant them and enjoy! They will all grow well in Louisiana.
Plant shallots September through early November. As the shallot set sprouts and divides into several stalks, the clump may be pulled and divided. Each stalk then may be harvested or set back in a row to grow and divide again all the way through May. After May, most gardeners wait until the next fall to plant again.
FOR MORE DETAILS, SEE PDF.