I was just just looking at the planting guidelines for Az for planting onions and shallots. It recommends long day shallots and short day onions. I've actually never even seen a day length listed on shallot varieties. Since the two are both planted at the same time of year, why would they have opposite day length requirements? I'm wondering if this is just a typographical error?

I understand the short day requirement for onions, they are growing through the winter. A long day requirement makes no sense to me at all.

One other question. With shallots, do I pull them all up, like garlic,and replant in the fall, or just pull what I need and let the rest continue to grow, like some types of perennial onions?