Growing large, sweet onions in East Texas requires a precise planting schedule and selecting the proper variety due to the region’s mild winters and rapid summer heat. Unlike northern climates, successful cultivation relies on maximizing vegetative growth before bulbing begins. The goal is to ensure the plants develop many leaves during the cool season, as each leaf corresponds to a ring in the final bulb, directly influencing its size. Navigating the brief window between the end of hot weather and the start of long days is the most important factor for a successful harvest.
The Critical Planting Window
The timing for planting onions in East Texas is concentrated in the late fall and early winter to allow for maximum growth during the cooler months. Onions are a cool-season crop that can tolerate temperatures well below freezing once established, making winter an ideal growth period. The plant must achieve a substantial size before the day length increases, which triggers the formation of the bulb.
For gardeners planting onion seeds directly, the ideal window is generally from October through December. Seeding requires an earlier start to allow for the necessary extended vegetative phase. Seeds should be planted shallowly, about a quarter of an inch deep, and thinned later to allow space for bulb expansion.
The most common method uses onion sets or transplants, which are small, dormant plants that offer a head start over seeds. The best time to plant these is typically from late January through mid-February. This timing ensures the transplants have robust growth before the lengthening days signal the plant to begin forming a bulb in the spring.
Selecting the Right Onion Type
The latitude of East Texas makes it necessary to plant only short-day onion varieties for bulb production. Bulbing is triggered by a photoperiodic response, meaning it is sensitive to the number of daylight hours. Long-day onions, suited for northern regions, require 14 to 16 hours of daylight and will only produce green tops without a large bulb in the South.
Short-day onions are genetically programmed to begin bulbing when the daylight reaches approximately 10 to 12 hours, which occurs in the spring in East Texas. If the wrong type is planted, the plants will never receive the necessary photoperiod to develop a large, mature bulb.
Popular short-day varieties highly recommended for the region include the ‘Texas Super Sweet 1015Y,’ ‘Yellow Granex’ (often associated with Vidalia onions), and ‘Texas Early White.’ These varieties are specifically bred to perform well in the mild winter and early spring conditions typical of the southern United States.
Site Preparation and Initial Care
Proper soil preparation before planting is foundational to growing large, healthy onions, as they are heavy feeders and possess shallow root systems. The planting site must offer full sunlight, and the soil needs to be loose, crumbly, and well-draining. Compacted or wet soil can lead to small bulbs or rot. Working the soil to a depth of 8 to 10 inches and incorporating liberal amounts of compost or organic matter improves drainage and fertility.
Onions prefer a slightly acidic to neutral soil pH. At the time of planting, a balanced fertilizer, such as a 10-10-10 mixture, should be spread across the bed and incorporated into the top few inches of soil. For transplants or sets, they should be planted shallowly so that only the roots and the very base of the plant are covered by soil.
After the initial planting, the plants benefit from early applications of a high-nitrogen fertilizer, such as ammonium sulfate, every two to three weeks until bulbing begins. Nitrogen supports the growth of the green tops, and since more leaves equal more bulb rings, this early boost is important for achieving a large final size. Consistent high-nitrogen feeding ensures the plant has the resources it needs to develop a robust top before the photoperiod signals bulb formation.