Mt Garfield Greenhouse sells certain onions already sprouted from seeds in packs, such as Walla Wallas and bunching (green) onions. These onions must be separated from each other before planting in order to achieve the sizing you want. Here’s a quick “how-to” for doing just that.
First of all, set yourself up with the plants, a bucket of water, and if you want, something to sit on. An upside down bucket works nicely as a perch; I recently treated myself to this groovy little tractor-seated scooter thingie.
Next, pop one of the cells out from the pack.
Swish the cell in the water to loosen the soil from the root ball. You can use your fingers to gently help the soil out.
Starting with an onion from an outside edge, gently tug it from the root ball with its own roots still attached to it. Set it in the water as you separate the rest of the onions from that cell.
Plant them in a prepared spot with the white part just under the surface. Green onions can be spaced rather closely, an inch or two apart. Larger onions should be spaced about 4 inches apart.
Repeat with the other cells, water them in and voila! They’ll be standing up and growing for you in no time. One pack of bunching onions usually keeps my family in fresh green onions for salads, omelets, and nacho garnish, etc. all season long.