Rich, well-drained soil–Covington’s Soil Builder w/shale
Onion sets and/or leeks
Hi-Yield Ammonium Sulfate (21-0-0) and Ferti-lome Gardener’s Special (11-15-11)
For Organic Gardens: Hi-Yield Blood Meal (12-0-0) and Happy Frog Organic Fertilizer
Plant onions and leeks in January – Leeks and onion transplants can grow very well in northeast Texas soils and are hardy in cool temperatures well below freezing.
Preparing the Soil:
Onions and leeks are best grown in full sun (minimum 6 hours) in well amended beds that have good drainage. Raised beds at least 8″ high work well. One way to ensure good drainage is by using expanded shale which is included in our soil builder. When preparing the soil at planting time, dig a 4″ trench for the length of the area you wish to grow onions and leeks in, spread Ferti-lome Gardener’s Special (11-15-11) along the trenches at the rate of 1/2 cup per 10 linear feet of row, and cover that fertilizer with 2″ of soil, then plant your transplants. For organic gardeners, we recommend our Happy Frog Organic Fertilizer.
Set onion plants out approximately 1″ deep with a 4″ spacing. If you want to harvest some of the onions as green onions during the growing season, you may plant the plants as closely as 2″ apart and pull every other onion to use as salad onions, leaving the remainder to become larger onion bulbs. Transplants should be set out four to six weeks before the last average spring freeze. 1015 Yellow and Candy onions tend to be the sweetest, with Granex onions having more bite.
Leeks don’t form bulbs, but develop long thick round edible stalks. To ensure the stalk remains white and tender it must be protected from sunlight, so plant seedlings approx. 4” deep with only a few inches of the leaf visible. Then throughout the growing process, mound soil up around the leek stalk so it’s blocked from sun.
Fertilization and Growing Tips:
Onions and leeks require a strong nitrogen feeding to produce well. Apply Hi-Yield Ammonium Sulfate
(21-0-0) at the rate of one pound per 20’ of row, three weeks after planting and every 4-6 weeks thereafter. Any fertilizer containing sulfur will tend to give onions a sharper bite. For organic gardeners, top dress with
Hi-Yield Blood Meal on the same schedule as above.
Always water strongly after feeding and maintain moisture during the growing season. When bulbs form, they can stand a much drier climate, however. Withhold watering the last 3 weeks before harvesting so your onions will store well.
Onions are fully mature when their tops have fallen over in the spring. After pulling from the ground, allow the onions to dry, clip the roots and cut the tops back to one inch. The key to preserving onions and to prevent bruising is to keep them cool, dry and separated. If your onions have flowered, they will be edible, but smaller. Use these onions as soon as possible because the green flower stalk which emerges through the center of the bulb will make storage almost impossible.
Harvest the leeks when the stems are about 1” to 2” in diameter. They will be ready about the same time onions are ready for harvest.