It turns out that walking onion (var. Catawissa) does reproduce in the far south, contrary to my earlier impression. I planted some bulbs in north-central fla around march 14, and of april 29 they were well into the bulbil-forming stage. I have agents checking on the progress, will update this thread later on. So it seems likely that day-lentgh is a non-factor for walking onions. The next question is whether or no the bulbils cure properly and can they stand a florida summer.