Potato onions are normally propagated by replanting bulbs. The bulbs are clones, so results are very predictable. Your potato onions will always look and taste the same when you reserve some of the bulbs to replant. Potatoes work the same way, which is presumably the origin of the term “potato onion.”
But what if you don’t always like to do things the “normal” way? What if you would like to explore the potential for new and different traits in potato onions? Then you need potato onion seed. Our seeds are produced from a patch that contains seven different varieties of potato onion to maximize open pollinated crosses. There should be reasonably good diversity in this seed with different skin and flesh colors, although the majority seems to be variations on yellow and white. When you get one that you like, you can keep it going indefinitely by replanting some of the bulbs every year.
Start and plant as you would any onion seed.
At least 100 seeds. Germination rate is about 66%.