I know very little about this subject but what sort of problems are you having ? Unless you are close to the water and are having salt issues I can't see what proximity to the coast would have to do with it ....May be a day length thing ,long day short day kinda' problem . I looked into growing onions some time ago and remember seeing mention of that.

I only mentioned being on the coast because our winters are usually much more mild than other parts of the state...didn't know if that had anything to do with them failing to bulb/produce onions.

And yeah, I was wondering if perhaps daylenght had anything to do with it even though they are supposed to not be daylength sensitive.

The long and the short of it is: I planted in the fall when I planted my garlic in a well amended raised bed, supplied extra N several times, gave what I thought was enough water. The plants grew and failed to form the onions. I've never had a problem growing onions from seed or garlic using pretty much the same methods so I'm a little perplexed why these did so poorly.

Probably Day length, you might check to see if there are other cultivars that will suit your needs. I've been interested in growing some for a while now but haven't run across any bulbs or seed...Did the tops brown off and dry or what?

Yes, the tops had started to fall over. That's what I understood to mean they were ready to harvest and when I discovered they had not produced onions.

I have successfully grown onions from seed before. The only problem is the usual varieties that grow here are not known for their storing capabilities. The potato onion is.

Well?...I hoped that someone with some real knowledge would join this discussion but I guess not. The Southern Exposure Seed Exchange has some info on their web site . That is the only place I've seen anything about Potato Onions. Sorry!Keep us informed.

sw_, did you plant the potato onions the same way you plant garlic? Did you keep the bulbs covered with soil? Last fall, I had an extra row of space in the garlic bed and decided to plant extra 1" diameter potato onions. I forgot about them this spring and left the soil over them as for the garlic. They did get weeded. When I went to harvest the garlic, I wondered what the Pot. Onions would provide-due to my negligence. Well the onions are 2.5-3.5" in diameter! They appeared as solos. I had never seen this in years of growing these. When I peeled and cut the onion crosswise, I found multi-cores.

My standard method of raising potato onions is to raise them on mini-ridges, 4-5" high. I only set the bulbs so the top is even with the soil. By the time the spring rains wash the ridges a bit, the potato onion sets (that were 1-1.5" in diameter), will develop into several green onions and then more sets. If any of the onions on the ridges appear covered, I remove soil from their sides.

The most green onions or sets from one of these has been 14. When I plant the 0.5" bulbs, they only grow to become 1-1.5", usually,solo bulbs.

The potato onions larger that 1.5" are the storage onions we eat in the winter. All others are replanted. This is our favorite green onion as it is the sweetest we have ever had. Next spring I will test the Brix level.

A friend told me of her family trick of holding the green onion clump to the ground in the spring, and pulling off 'selected' green onions, then, allowing the remaining cluster to continue growing.

Am in zone 6b, south central KY, where onions grow deliciously as long as there is super drainage, but adequate water.