Robyn, my onions this year, for the first time in a long time are large.
The fact they were watered at least for thirty minutes every other day is the only thing I did that was different from past years.
I kept them weeded and did not plant them as close together as I used to which probably helped also.
When I have used onion seed I would get some small keepers but they are always going to be behind sets or plants.
One thing you could try to get some answers, buy a couple of bags of cheap garden soil next year and make a small, no bigger in size than a single bag, bed with that soil about six to twelve inches deep.
Put six onion sets, plants or seeds in that area.
If that bed out does your regular garden soil, you will know it is partly the soil.
