There are many different types of onions, there is one for every taste and purpose, from tiny pearl onions to big Bermudas. Gardeners usually use three methods to plant onions: planting sets, transplants, and seeds.
Onion sets are little onion bulbs, which when planted in the ground come out of their dormancy and continue to develop. Planting sets is the most effortless method to produce a great amount of big onions. Plant sets 2 to 4 weeks before the average time of last frost in the area you live in. In mellow winter atmospheres, plant onion sets in fall or winter.
Put the sets in a shallow furrow and cover with simply enough soil to leave their pointed tips at the surface. The distance between onions ought to in the end be 4 to 6 inches, contingent upon the mature size of the variety, however you can put the sets nearer together at first and collect thinnings for use as green onions.
However, the only problem here is that there are just a few varieties suitable for this kind of growing. When you go to buy your sets, pick the ones that are about half an inch in diameter. Those are the best.
With a greenhouse or indoor light setup, you can produce your own bundles of bareroot onion transplants or, if you don’t have the conditions, you can just buy them. In the north, sow seeds in a level of seed-beginning medium 8 to 10 weeks before the last frost, to be planted outside around a month and a half later. In the south, time the seedlings to be set out in fall or winter. Thin the developing seedlings in the level to remain no less than 1⁄2 inch separated in rows, around 2 inches distance between them, so they will be less demanding to isolate at transplant time.
Set the flat in a shielded spot outside for a couple of hours a day, continuously adjusting them to an entire day of direct daylight. This way you will harden the seedlings. When the day for planting comes, lift the seedlings with caution from the level and shake the soil from their roots. If the tops have developed to be tall, trim them back to around 6 inches.
Dig a trench for the seedlings and place them a little bit deeper than they were in the level. Similarly as with sets, seedlings can be planted nearer than their definitive separating of 4 to 6 inches, with the additional products reaped as green onions.
In any case, clustering onions or scallions are faster to develop, and they can be seeded specifically into the garden. Sow seeds outside starting about a month prior to the last frost date and afterward again at regular intervals through fall to continual harvests. In the south, the season for planting onion seeds is fall through spring. Begin with fresh seeds, or seeds that are close to a year old (but no more), since onion seeds lose their vitality away rapidly.