Nothing starts the new year off right like a good conversation about onions! Onions are fun to grow and even more fun to harvest. If you want to give them a try in your garden this year, now is the time to start preparing!
Did you know that Texas is well-known for its onion crop? The Rio Grande Valley, Winter Garden area, High Plains, and far West Texas had 7,000 to 7,500 acres of onions in 2020. Sweet yellow onions like the Granex and Texas 1015 are well known all over the world.
Sweet onions were first grown in Texas in 1898 when the Bermuda onion was planted near Cotulla. By 1904, approximately 500 acres of Bermuda onions were grown in Texas to meet the enthusiastic demand in the United States. In the 1920’s the demand for Bermuda onion seed was so great, the Canary Island growers could not send enough quality seed. In 1933, the Texas Agricultural Experiment Station started an onion breeding program that eventually produced the famous varieties we enjoy today like the Granex and Texas 1015.
Onion seeds should be planted in October in Texas, or you start with onion transplants in mid-January. First, an onion forms a top, and then it forms the bulb. Each leaf on the top of an onion forms one ring of the onion. The size of an onion bulb depends on the number and size of the leaves at maturity.
Onions mature based on day-length. Long-day onions will quit forming tops and begin to form the onion bulb when daylength reaches 14-16 hours. Short-day onions begin making bulbs when day-length is 10-12 hours long. Short-day onion varieties are recommended for our area such as: Texas 1015, Red Burgandy, Granex, Early Grano, and Southern Belle.
Plant onion transplants about ¾ to one inch deep with four-inch spacing between plants. You can plant them closer together if you want to harvest some green onions during the growing season. Onions are ready for harvest when the tops fall over.
Onions require a high source of nitrogen like ammonium sulfate (21-0-0) applied at the rate of one cup per twenty feet of linear row. Fertilize three weeks after planting and then every three weeks; water immediately after fertilizing and maintain moisture during the growing season. Stop fertilizing once the neck of the onion starts feeling soft.
When you harvest onions, allow them to dry, and clip the roots and tops back to one inch. Keep onions cool and separated to prevent bruising. Onions can last a long time if you store them in a cool, airy location.
For more information about growing onions or other gardening questions, contact County Extension Agent Kate Whitney at the AgriLife Extension Office at 512-943-3300.
