Planting onion bulbs is simple, but doing it correctly makes all the difference between a small yield and a thriving harvest. Uriah Israel of Texas Small Farmers & Ranchers CBO breaks down the process step-by-step—from recognizing the right side of the bulb to understanding sunlight and watering needs.
Understanding the Onion Bulb
Onions can be planted three ways: by seed, by set (a young seedling), or by bulb. Bulbs are the most common choice for quick, predictable results. Each bulb has two distinct ends—the fuzzy bottom, where roots grow, and the pointed top, where leaves emerge. Identifying these correctly ensures the plant develops in the right direction.
Planting Depth and Spacing
Use a stick or dibber to make holes about one inch deep. The bulbs should be spaced 3–4 inches apart within a row, with each row about 6 inches apart. Planting in neat, even rows allows for better airflow and easier watering. For home gardens, three rows per bed create a good balance of space and productivity.
When inserting the bulbs, keep the root side down and the pointed side up. After placing them in the soil, gently cover without pressing down too hard. Onions prefer loose soil that allows moisture and oxygen to circulate freely.
Consistent Watering Is Key
Onions don’t hold water well, so regular irrigation is essential. A drip irrigation system or consistent manual watering helps maintain even moisture. Especially in warmer climates where temperatures stay high, daily watering ensures bulbs grow steadily and resist drying out.
Sunlight Requirements
Different onion varieties require different daylight exposure.
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Early varieties: 8–10 hours of sunlight
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Intermediate varieties: 10–12 hours
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Long-day varieties: 12–14 hours
Selecting the right type for your region’s daylight length determines how large and flavorful your onions will become.
The Takeaway
Planting onion bulbs is both rewarding and practical. With the right spacing, regular watering, and appropriate sunlight, onions will mature into firm, flavorful bulbs ready for the kitchen.
