Would a day without an onion be like a day without sunshine? For my husband and I, it would be. We must be onion junkies. That’s probably a good thing, since onions are very good sources of immune-supportive vitamin C. They are also a good source of enzyme –activating manganese and molybdenum, as well as heart-healthy vitamin B6, fiber, folate, and potassium. Mostly we eat lots of them because we love the taste.
Here in Ellis County, the recommended planting dates for onion sets are from Jan. 15-Feb. 10. That makes December the right time to start preparing your planting beds and looking for onion set varieties that grow well here. If you wanted to plant onions from seed, that should have been done back in October.
Did you know that onions come in short, intermediate, and long-day varieties? Short day onions are recommended for our area. There is a new variety out this year, Texas Legend. I plan to try some of these. Other short day varieties are 1015 Texas Supersweet, Texas Early White, Hybrid Southern Belle Red, Yellow Granex, White Bermuda, and Red Creole. Last year I tried some intermediate day varieties and had pretty good success with Borettana Cippolini and Red Marble Cippolini. The Red Torpelo Tropea did not do very well; but alas, I will try again this year because they are such cute little gourmet onions with wonderful flavor.
Last year we planted onions in three different locations: raised beds in the garden, along the property line in our “row crop” area, and in the berm in front of the house as a part of our edible landscape. Since onions benefit from reliable and consistent moisture (not soggy or wet), the onions in our raised beds with drip irrigation system were the most robust. Our onions in “row crops” and in the berm also did well. All of these planting sites are raised at least four inches, which provides the onions good drainage. Since we do not irrigate two of the areas, we used wood mulch about two inches deep to help these areas retain moisture. We did water all of the onions when we planted then, but only consistently watered the ones in our garden raised bed area. In addition to adding lots of compost to the soil prior to planting, we side-dressed the onions with organic fertilizer with a high nitrogen content at planting and then every three weeks.
Onions are susceptible to foliar diseases that can cause rotting during storage. These types of diseases are not noticeable during the growing season, but may be prevented by spraying the plants with a fungicide approved for use on food crops every couple of weeks. If you use a fungicide, be sure to follow the directions on the product label.
Now is the time to start preparing your planting beds for a successful onion crop. Just remember these tips. Your site selections should be sunny and well drained. Soil preparation should include lots of compost. Plant onion varieties recommended for our area. Spacing between onions should be about four inches. Water and fertilize onion sets when planted. Drip irrigation works best for onions. If you can feel moisture in the soil when you stick your finger into the ground up to your first knuckle, then the onions are properly watered. Water only when the soil has dried out. Fertilize with a high source of nitrogen, e.g. 21-0-0 every three weeks and use a fungicide every couple of weeks. Use mulch to conserve moisture and reduce weeds.
Onions are fully mature approximately 110 days after planting. A visual cue that your onions have matured is the tops will fall over. To harvest, lift the onions out of the ground and allow them to dry on the ground in the sun. I actually use an old trampoline as a drying rack for onions and garlic. Once the onions have dried so the outer layer of skin is papery, trim the roots from the bulb and cut back the dried foliage. Store the onions in a cool, dry, well-ventilated location.
For more information on growing onions, visit http://aggie-horticulture.tamu.edu/archives/parsons/publications/onion/oniongro.html.