The successful cultivation of onions culminates in a timely harvest, which significantly impacts both the flavor and the potential storage life of the bulbs. The moment of harvest is dictated by precise visual signals from the plant, not a calendar date. Recognizing these physical cues is the most reliable method for determining when to lift the bulbs, ensuring maximum energy transfer from the foliage to the storage structure. This is important for Texas growers to achieve the signature sweetness and ensure proper preservation.
Visual Signs of Onion Readiness
The most dependable indication that an onion bulb has finished growing is the lodging or collapse of the green tops. This occurs when the neck, where the foliage meets the bulb, softens and bends over, signaling the plant has stopped transferring carbohydrates. It is recommended to wait until at least 50% to 75% of the plants have their tops fallen over before initiating the harvest.
Before the tops fall, the foliage often begins to yellow and wither as the plant directs its remaining energy into final bulb maturation. This yellowing confirms that nutrient transfer is concluding. Once the neck has completely softened, the plant is sealed off, and the onion is ready to be pulled. Harvesting too early, while the necks are still rigid, prevents the bulb from fully developing its final layers and limits storage potential.
Texas Onion Types and Expected Harvest Windows
The majority of Texas-grown onions are short-day varieties, programmed to begin bulbing when daylight reaches 10 to 12 hours. This adaptation suits the southern latitudes, where the difference between winter and summer day lengths is less pronounced. Popular Texas varieties include the ‘1015 Texas Super Sweet,’ ‘Yellow Granex,’ ‘Texas Legend,’ and ‘White Bermuda,’ all known for their mild, sweet flavor.
The expected harvest window typically falls between late spring and early summer, generally from May through July, depending on the planting date and regional microclimate. Onions planted in the fall or mid-winter usually mature during this period. Attempting to grow long-day varieties in Texas will result in the plant failing to bulb properly, as the required 14 to 16 hours of daylight is never reached.
The Proper Way to Pull Onions
Harvesting requires care to avoid damaging the outer skin of the bulb, since any bruise or cut provides an entry point for pathogens that cause rot. Stop all watering at least one to two weeks before the planned harvest to allow the soil to dry out completely. Pulling bulbs from dry soil helps ensure the outer papery layers remain intact and assists the initial drying process.
To lift the bulbs, gently loosen the soil around them with a garden fork or trowel, then pull the onion up by the neck. Take care not to rip the foliage from the bulb. Immediately after lifting, lay the onions out in the garden for a few hours, or up to a full day, to dry the exterior skins. If the sun is intense, cover the bulbs with the tops of other harvested onions to prevent sunscald and spoilage. Do not wash the bulbs, as introducing moisture delays curing and encourages rot.
Curing and Storing Your Texas Harvest
Curing is a mandatory post-harvest process that prepares the onion for long-term storage by drying the neck and outer layers into a protective sheath. This step is important for sweet, short-day varieties, which naturally have a higher moisture content and shorter shelf life than pungent counterparts. Curing effectively seals the neck of the bulb, preventing moisture loss and blocking the entry of decay-causing organisms.
The ideal curing environment is warm, dry, and well-ventilated, with temperatures ranging from 75 to 90 degrees Fahrenheit. The bulbs should be spread out in a single layer on screens or racks, protected from direct sunlight and rain, for two to four weeks. Curing is complete when the neck is completely dry, tight, and contains no moisture, and the outer skin is papery and rustles to the touch.
Once fully cured, the roots should be trimmed close to the bulb, and the tops cut back to about one inch above the neck. The cured onions should then be stored in a cool, dark place with excellent air circulation. Storage methods include using mesh bags, braiding them together, or placing them in crates. An optimal storage temperature is between 32 and 40 degrees Fahrenheit, which maximizes the storage life of these sweeter varieties.