The onions and shallots don't get a foliar. I use a tablespoon of organic Espoma BulbTone at planting, in the bottom of the hole, before I put the clove in, for the shallots. I plant as early as I can in October here in New England so the roots can establish before the ground freezes. They are heavily mulched at planting. Besides pulling the occasional weed that's all the shallots get.

The onions are started in March inside and planted outside in May. The soil is amended with a mix made from a soil test for that garden. They are mulched (if I have it, which I didn't for most of these) when planted. They don't get a foliar spraying either during the season.

So except for weeding, that's all I do during the season. The spacing is important, both of plants as seedlings and in the row, and of the rows themselves. Weeding is also important, as alliums do not like competition. That's why I am so surprised at how big the ones I am finding are.

The weeds got way ahead of me, but I guess the onions had developed a good enough root system, and the soil was good enough, they grew large anyways.