Onions and Garlic

People are getting anxious for "the big stink" to begin. Onions and garlic WILL be maturing before too much longer. But anxious "growers-of-stink" always have some last minute concerns. The first of which is, “will the onion EVER form the bulb, and/or, can they in some way "stimulate" bulb production and size?”

Recommended varieties for this area are the Texas A&M 1015& (Supersweet), Granex or Grano. If, last fall, you planted seed, or planted transplants this spring, of the recommended varieties, the onions HAVE to bulb sooner or later--BE PATIENT!

However, if you planted bulblets or seeds of the wrong varieties, YOU'RE IN TROUBLE! Bulblets should NEVER be planted because the proper varieties are not available. The onion, depending on the variety, bulbs during either long day conditions (13 to more than 14 hours), intermediate conditions (11-1/2 to 12-1/2 hours) or short day conditions (10 to 11 hours).

Long day varieties will not bulb in Central and South Texas because the days are not long enough. In this area, long day types are grown as green onions or scallions. Long day varieties from bulblets will produce huge plants, large necks, big blooms and no bulbs. Texas is the home of the sweet onions of the world. For the history of the sweet onion, see:

http://aggie-horticulture.tamu.edu/plantanswers/publications/onions/onionhis.html

For more information about onion varieties and recipes, see:

http://aggie-horticulture.tamu.edu/plantanswers/publications/onions/onions.html

The other would-be, size-enhancing technique is soil removal. Is it necessary to remove the soil from around onion bulbs in the spring to make large bulbs? Absolutely not! Bulbing of onions is controlled by variety, temperatures and the length of day. The onion WILL bulb when the required conditions are met. Removing soil around the base of the plant will not increase bulbing, although it may appear to do so because the bulbs are visible. This operation may do more damage than good, especially to white varieties of onions. Removing the soil from around white onions results in sunburning, which turns the top of the bulbs green.

Next comes the floral question--most folks wanted to grow onion bulbs, NOT onion flowers! What causes bulb onions to send up flower stalks? Flowering of onions can be caused by several things, but usually the most prevalent reason is temperature fluctuation. An onion is classed as a biennial, which means it normally takes 2 years to go from seed to seed. Temperature is the controlling or triggering factor in this process. If an onion plant is exposed to alternating cold and warm temperatures, the result is the onion plant going dormant, then resuming growth, then going dormant and resuming growth again. The onion bulbs prematurely flower or bolt. The onion is deceived into believing it has completed 2 growth cycles, or years of growth in its biennial lifecycle so it finalizes the cycle by blooming. Flowering can be controlled by planting the right variety at the right time. Use only transplants that are pencil-sized, or smaller, in diameter when planting in early spring. In the early fall, always plant seed, NEVER transplants.

What can you do if flower stalks appear? Should the flower stalks be removed from the onion plants? Suit yourself, but once the onion plant has bolted, or sent up a flower stalk, there is nothing you can do to eliminate this problem. The onion bulbs will still be edible, but probably will be smaller. Use these onions as soon as possible because the green flower stalk that emerges through the center of the bulb will make storage almost impossible. How will you know when onion bulbs as large as they are going to be? The onion is one of the few vegetables that signal you when it's ready to be harvested. An onion bulb is mature when the top bends at its narrow neck and falls over. When the bulb reaches this stage, it will not enlarge any further and may as well be harvested. Until the tops fall over in mid-to-late June, plants should be fertilized with ammonium sulfate (1/2 cup for each 10 feet of row) every month.

Some folks want to rush the process. They always ask, “Should I break over the tops of my onion plants to get a larger bulb?” Breaking over the tops of onion plants will not increase bulb size but can prevent bulb enlargement. Onion bulbs increase in size as sugars manufactured in the top are translocated to the bulb. If the tops are broken, this process stops, preventing further bulb enlargement.

Once you produce a large onion, for goodness sakes, DON'T let the bulbs rot. In most cases, onions decay in storage because of neck rot, which is caused by a soil-borne fungus. When harvesting onions, wait until the tops begin to dry and fall over. Once this happens, lift the plants and allow them to dry. After drying, clip the tops and dry the cut area for 1 to 2 days. By doing this, the cut tissue will dry, eliminating a possible site for infection. Then, place the onions in a well-ventilated area and in a container that allows free movement of air around the onions. If the onions are to be stored, a good fungicide program using chlorothalonil (Daconil, Multipurpose Fungicide or Fertilome Broad Spectrum Fungicide) or maneb every 7 to 10 days during the growing season is important to prevent diseases, such as tip blight and purple blotch, from entering the bulbs.

What about another stinker—garlic? A first word of warning--DON'T plant garlic in the spring! Bulb formation in garlic occurs in response to the lengthening days of spring, and bulbing and maturity are considerably hastened if temperatures are high. In addition to these requirements, the dormant cloves (divisions of the large bulb) or young growing plants must be exposed to cold temperatures between 32 and 50 degrees F. for 1 or 2 months in order to initiate bulbing. Plants that are never exposed to temperatures below 65 degrees F. may fail to form bulbs. With fall plantings, the cold treatment is accomplished quite naturally throughout the winter, but a spring planting spells disaster.

Seedstalk formation (bolting) of garlic is not induced by exposure to fluctuating temperatures, as is the case with onions. This means that a wide range of fall planting dates is permissible for this crop. Seedstalk formation is also not damaging to garlic since the cloves are arranged around the seedstalk and will be removed from the dried seedstalk. Conversely, the edible onion bulb is penetrated by the seedstalk that is hard when the bulb is harvested, but prematurely decays causing loss of the entire bulb in storage.

When the tops become yellowish and partly dry, garlic is ready for harvest. The bulbs are usually pulled and gathered into windrows. The tops are placed uppermost in the windrow to protect the bulbs from the sun, and the garlic is left in the garden for a week or more to dry (cure) thoroughly. Curing can also be accomplished in a well-ventilated shed. The cloves must be thoroughly dried before being stored. When properly cured, garlic stores well under a wide range of temperatures.

NOW you know all that you need to know about these delightful spring stinkers! Don't blame me if you over-indulge and are forced by loved ones to wear odor-eaters on your lips!