Potato Onion Report 2025

[A. Pel]

Well, I have had quite a good year on my Potato Onion Resurrection Project.

For those that don't know, Potato Onions (or multiplier onions) are onions that are bred to split into bunches of multiple bulbs from a single planted bulb. You then plant one of the bulbs back and eat the remainder - much like potatos (hence the name).

There are existing lines of heirloom Potato Onions but they have the reputation of rarely setting viable seed. This makes it very difficult to work with them from a breeding perspective. I am using selective breeding of various common onion varieties to produce a variety of onion with Potato Onion characteristics that will readily split and also set viable seed.

Here is a write up on this years progress: 2025 Potato Onion Report There is a lot more detail of the projects progress and goals on that page.

As an example here is a bunch of 4 - I now have about 11 bunches of 3 and 4 onions each. All of reasonable size.



Here is a pic of the 3 and 4 bunches for the 2025 season. The white bar in the middle is a measuring stick with both centimeter and inch markings.



Here is a pic of the doubles (bunches with two onions)

[whwoz]

Do you have shallots available to you.  They are the same species as potato onions and may help your genetic diversity.  What I understand is that multiplier onions planted before winter will flower, those planted later will not.

I planted Red Shallots, Golden Shallots, Red Banana Shallots, Golden Banana Shallots and an unnamed potato onion in Mid April, middle of autumn here and some of all varieties are going to flower.  Will be interesting to see what happens as we may not have suitable pollinators around


https://www.tomatojunction.com/viewtopic.php?t=6641

More information plus photos in the link

[A. Pel]

Do you have shallots available to you.... 

I tend to think of shallots as heirloom French potato onions. However, they do tend to have a distinctive taste. Not bad, but different from regular onions.

In the early days, I considered using them to introduce splitting characteristics into the gene pool with the thought of breeding the taste back out but keeping the splitty-ness. I also considered doing the same with  spring onion/scallions etc. and then breeding the small size back out.

Ultimately, I decided to hold off for a year or two in order to see how things might settle out before taking drastic steps like that. I am quite pleased now that I did. At the time I took the notion that most single bulb onion types were probably descended from multiplier type ancestors. It turns out mongrelizing various common single bulb onion varieties by promiscuously crossing them with each other unlocked the latent "potato onion" genes that they were already carrying.

So the introduction of shallots was always an option - but one I was saving as a last resort. Interestingly, a small percentage of my onions come out as distinctly shallot like - so I'm thinking there are some shallot genes in there already.

[Richard Watson]

After many years of hoping my potato onions would produce flowers, I now have flower stems about two weeks away from opening. What I tried this time was to plant them along side some standard flowering onion plants which I think had triggered the potato onions into reproducing. I'm now going to cover both blocks of flowering onions with insect nests and only open one up every other day to let the flies and native bees do there thing.