Bunching onions, commonly recognized as scallions or green onions, produce flavorful, slender green stalks rather than large, globe-shaped bulbs. They are often grown using the “bunching” or “clump” method, where multiple plants are cultivated together from a single spot. This technique maximizes yield in a small area and requires a specific approach to direct-sowing the seeds.
The Recommended Number of Seeds Per Hole
The direct answer to how many bunching onion seeds to plant per hole is to aim for a small cluster of between four and six seeds in each prepared planting spot. This range accounts for the notoriously inconsistent germination rate of onion seeds. The goal is not to grow a single, large plant, but an entire, ready-to-harvest clump, which bunching onions naturally tolerate. These seeds should be sown shallowly, ideally between one-quarter and one-half inch deep, and covered lightly with fine soil or compost. Bunching onions prefer a well-draining soil with a slightly acidic to neutral pH, generally between 6.2 and 6.8, which supports successful initial germination.
The Essential Step of Thinning Seedlings
After planting, it is likely that more than the desired number of seedlings will emerge, making thinning necessary. Thinning is the act of removing weaker or excess seedlings to ensure the remaining plants have adequate access to light, water, and soil nutrients. The best time to perform this task is once the seedlings have established their first true leaves and have reached a height of about two to three inches. The correct method is to use a small pair of sharp scissors or nail clippers to snip the unwanted seedlings at the soil level. Avoid pulling them out, as this risks disturbing and damaging the delicate root systems of the keeper plants. The final objective is to leave three or four of the healthiest, most vigorous plants in each clump to grow to maturity.
Establishing Final Row and Clump Spacing
The spacing between the center of one clump and the center of the next clump should be between six and eight inches. This distance provides enough room for the cluster of onion stalks to expand fully without competing for resources with a neighboring bunch. If the bunching onions are being grown in traditional garden rows, the distance required between those rows should be between twelve and eighteen inches. This wider row spacing allows the gardener sufficient room to walk, weed, and perform maintenance like hilling up the soil, which can help blanch the lower portion of the stalks for a whiter, milder flavor.