Bitty potato onions is same as multiplier onion. It forms bulbs on the bottom and will have anywhere from 4 to as many as 10. you would keep the largest to eat and they are a good "keeper" onion and will store well. Then you take the smallest of the bulbs and replant those, therfore you won't ever have to buy onion sets again. the best time to set either of these onions is in the fall. and you harvest them in spring and summer. I got my starts from a company called Southern Exposure Seed Exchange". They carry mostly heirloom seeds of all kinds.Thanks Errol, having them self seed or replanting the bublets is a great way to save money. I always find that there are too many onion bulbs in the bag when I buy them and they end up going to waste. Thanks for the tip I will try Egyption Walking onions this year. Oh yah, what are potato onions?