(I have a very similar post for garlic...)

Not my first year with onions but the results seem to be always the same so I ask:

The results, (generally) early strength and growth -- with what seems to me to be too soon falling over & leaf browning -- and on harvest the results are meager. Some of it is nothing more than the set I put in the ground.

Specifically: Planted 2 cultivar sets from reputable biz in late April. All sprouted well. The leaves stood up, for a few weeks. Then they all fell over (I'm amazed when I read posts where people say their onions are standing up (in July) and show no signs of browning. Come to think of it I remember as a kid home garden onions developing seed heads...

When I do pull the brown ones I get about 80% not much bigger than the original set, and then 15% maybe 2x the set and the remaing 5% about 1"-2" diameter. There are a few that are still on the ground, green but there's none with more than a single "leaf" nor any standing up.

What/why could be causing such (stunted?) growth or (early?) death?

Please, any advice, wisdom, thoughts, anything please?