Can anyone tell me how onion sets are produced? I believe they are produced on the seed head somehow but I have not been able to find any info in my gardening books
Onion sets are specifically grown from onion seeds and are immature onions. The tree onion produces small bulbils instead of a seed head and if left the bulbils fall over and root in the ground producing a new plant the following year. The bulbils can also be used in cooking.
as lesley says sets are grown from seed but they are then subject to a special heat treatment to allow them to be stored and transported you or i cannot replicate this