How to grow onions
First decide whether you want to sow onions or grow onion sets. If you sow in March/April, you can expect the harvest in August/September. If you start with onion sets, you have a head start. You can then already harvest in June/July.
Sow onions in rows. Loosen a line of soil and scatter the seeds in a seedbed. Make sure the soil does not dry out. After emergence it is best to thin them out a little, then you get thicker onions. An onion needs space to grow. Let them grow all summer and fertilise them at least once with an organic fertiliser. This way you get many and bigger onions.
Around August/September, the leaves turn a bit yellow and fall off. Let them dry. The best way to do this is to hang them up. The wind must be able to blow through them. When the praise is dried enough, you can remove it. The onions can then be stored inside in a cool dark place.