Potato onions- the easy-to-grow “perennial” crop

Potato onions-  the easy-to-grow “perennial” crop - and one of the most useful!


(picture above is from another Permies thread on potato onions, linked below)

Potato onions are a type of multiplier onion that makes multiple bulbs, rarely sets seed, and is not a topsetting onion like a walking onion.  I'itoi onions are another multiplier. Shallots are also multiplier onions, but potato onions have a slightly different flavor and potato onions usually store much longer than shallots.  I've kept a batch for over a year.  That's a resilient plant!

Potato onions are often quoted as being one of the most productive food crops. I  probably eat more plants form the allium family than any other, so I think they are wonderfully useful to have on mass.

Your options for growing them are to buy small bulbs and plant them in either fall or spring, or you can start them from seed.  However, potato onions are becoming increasingly rare and now only a few companies sell the bulbs.  This is truly a crop that could be lost to “modern” foods.

Like most people, I originally started growing potato onions from little bulbs.  I thought it was the only option. I was also annoyed by how tiny the bulbs usually were.  Eventually I discovered that a  grower (Kelly Winterton) had been developing larger bulbs from the genetic diversity contained in the seeds.  The problem was they rarely seeded.  

Winterton seems to have incredible dedication to resurrect these genetics, as this is a long term project.  For this reason, if you ever see your potato onion go to seed, let it and save the seed if you can. You never know what genetic diversity are hidden in that batch.  If you are curious about how this works with seeds, read some of Joseph Lofthouse's posts about landrace seeds.

I grew Winterton’s potato onions from seed in Oregon, but now in the SW I am starting a new batch from fresh seed.  I want to find my own variety that does well here in NM.  The other advantage of starting from seed is that you tend to start out disease-free, whereas bulbs or starts can carry disease with them.  

The germination rates so far are about 90% germination for Green Mountain (very fast germinator), 70% of the SESE batch, and 60% of the Dakota variety.  I think the Dakota variety was just slower, because more are popping up after a month.  Also, 90% of his perpetual leek seed sprouted.

(Here’s a tip for you, don't drop the whole seed tray on the floor.  That’s an obvious tip, but that's what I did.  And this is why I don't have a picture of my germination results, as they were artificially stunted by my having to put the soil and starts back into the cells.)

An excellent thread on growing potato onions from seed, with lots of pictures is here: Potato Onions from true seed on Permies

Here is a collection of historical references from older books plus personal experiences with potato onions, in a document by Steven Edholm of Turkeysong [farm/camp/center], from his Skillcult website:

The Historic Potato Onion: A compilation of early references by Steven Edholm

I enjoy reading those old references.  Many thanks to Steven for putting them into one document!

Possibly the most detailed, and current, write ups on potato onions are by Kelly Winterton, a committed grower who has developed new, larger varieties from seed:  The Potato Onion Facts Booklet by Kelly Winterton

And this one:  Resurrecting the Potato Onion

More about potato onions from this Australian permaculture blogger: Mudflower talks about the disappearance of potato onions in Australia, plus how they grow in AU

I find it interesting that these plants were once popular in many parts of the world, but are now hard to find.  Seems like the perfect time for a resurgence!

You can buy bulbs or seeds from these sources currently:

Kelly Winterton, seed and bulbs  Kelly Winterton true potato onion seed and bulbs

FullSkyFarm on Etsy sells bulbs and seeds from three varieties, including Green Mountain   Potato onion bulbs and seeds from Full Sky Farm

Southern Exposure Seed Exchange - this variety bulb might be better for southern growers   Yellow potato onion, Hill Onion, Mother Onion, or Pregnant Onions from SESE

Fedco - these bulbs might be better for northern growers, but I'm not sure how long the last in storage, as they refer to this variety as "shallots"  Fedco multiplier onions, yellow moon dutch shallots

Peaceful Valley Farm and Garden Supply typically has them seasonally, and also has this growing guide: Peaceful Valley's potato onion growing guide

Filaree Farm carries yellow potato onion bulbs. Filaree also claims to have the largest selection of garlic in the US, and organically certified as well. Filaree Farm yellow potato onion bulbs

Territorial Seed Co used to carry bulbs they seem to be out as I write this.

Piedmont Farm and Garden in south Carolina sells white potato onions: Piedmont Farm and Garden white potato onion bulbs

In Canada, Vesey's sells bulbs: Vesey multiplier onion listing - Canadian

You may also be able to find more sellers on e-bay or Davesgarden.

If you would rather watch a video series to learn about potato onions, check out these videos.  It’s nice to see what they look like before you put time into growing them.  My results in Oregon looked similar from seed.  Lots of big ones, much larger than the potato onions I’d previously grown from purchased bulblets.

I love potato onions. I'm still eating bulbs that were harvested last fall (seven months ago). They have stored perfectly.

Thank you Kim I never heard of this onion and look forward to trying it.

The trick is not to eat the big one's but to let them multiply when dashing to the onion patch. One might think I'd learn this from experience.

I really wanted to try the potato onion, but have to be careful with my money, so I ordered 50 yellow potato seeds, and 50 Green Mountain potato onion seeds.  I live in N. California zone 9b.  From everything I have read the seeds should have been started in doors a couple of months ago.  I was thinking I would plant 1/2 of the seeds and see what happens, and put what is left in the refrigerator, and plant them in the fall.  I would love any advice, or info you have.  Should I soak the seeds I'm going to plant first?  Should I start them on a damp paper towel?  Just plant them and see what happens?  Excited  to try something new.  Thanks

Jen Fulkerson wrote: From everything I have read the seeds should have been started in doors a couple of months ago.  I was thinking I would plant 1/2 of the seeds and see what happens, and put what is left in the refrigerator, and plant them in the fall.  I would love any advice, or info you have.  Should I soak the seeds I'm going to plant first?  Should I start them on a damp paper towel?  Just plant them and see what happens?  Excited  to try something new.  Thanks

I started mine exactly one month ago in a tray indoors and I'm working on hardening them off now.  They are about 4 inches tall, but thin still.  They started very fast with no special treatment.  I think the start half, save half idea is pretty much always a good bet!

In Oregon, I started them in the ground and that worked too.  Here in the desert we have a soil crusting issue, plus everything dries so quickly, plus I'm told quail love little seedlings... so I went with indoors.  Onion seedlings seem very vigorous in my experience.  I also started perennial leeks and garlic chives.  They all shot out of the trays!  Some of the fastest plants.  The garlic chives are thicker, but they are only 2-3 inches tall.

Good luck Jen!  I'd love to know how your project goes, too.  I will try to post again on them later this year.

Jen - I think a lot of those recommendations about seed planting are to do with ensuring enough time in the year to get a mature crop. I'm pretty certain that would not apply in this case, as you are trying to get a perennial established. I figure you should crack on and see how it goes.

Supposedly I'itoi onions don't set seeds, but many people have claimed that about potato onions, so I wonder.  Has anyone ever seen an I'itoi set seeds?  I'd love to try and adapt them to my place here in Maine via growing seeds.  I planted some years ago and one small clump has managed to hang on for me, but I feel like I could loose them any year.  I'm hoping they might some day set seeds for me due to the shock of living here so that I can plant those and see if any of the offspring maintain the flavor, but thrive here.  

In the meantime I'll keep an eye on mine and try and figure out why this little clump survived while all the others perished.  It's about 6 inches from my foundation so that may well be a part of it.  When I can divide it I'll spread them along that wall hoping that will be ok for them.

Ok, googling for a bit I found this picture of an I'itoi getting ready to open it's flowers (the gardener couldn't wait to eat the them!):



Found it in this thread where a few people reported an odd I'itoi flowering.  I wish someone had reported on whether they set seed, top sets or nothing.  Perhaps crossing them with seed grown shallots might be interesting.  I'll keep this in the back of my mind for the off chance that mine ever flower.  Perhaps I should pot a few up so that the temperature can swing more in case that explanation is valid.  I'll wait until I have more before I give that a go.  Hope springs eternal! :)

Kim Goodwin wrote:
You can buy bulbs or seeds from these sources currently:
FullSkyFarm on Etsy sells bulbs and seeds from three varieties, including Green Mountain   Potato onion bulbs and seeds from Full Sky Farm

I just placed an order from this source, finding them in stock on three types of potato onion seeds and one type of bulbs.  They are from a nearby-to-me bioregion with reasonably comparable growing conditions.  And I figure that three different kinds of seeds gives me a decent start on a Lofthouse-style landrace.

I have been growing nondescript green onions from the grocery store, which in this climate seem to be perennial -- they persist and flower for several years without ever seeming to die back.  But they don't set seed, they don't multiply, and they aren't really an ideal crop, although I keep them around because they are completely idiot-proof, zero work, and any allium is better than none in hard times.   They grow about four feet tall, the green stems are pretty tough and fibrous (except for new growth), and the white part is leek-shaped and quite variable: some are tough and fibrous, some are tender and sweet like a fine shallot.  I usually harvest an armload at a time (half a dozen plants) and chop/freeze the green parts for making vegetable stock.  The white parts need to be tested individually; tough ones go into stock, tender sweet ones go into the fridge in a cleaned and peeled state for use in salads, sandwiches, and cooking.  

I was fascinated/delighted to read this thread because, although I had seen the phrase "potato onions", I had no real notion what they were.  It seems to me they might easily replace my "monster green onions" as a low-effort perennial allium that's closer to "real onions".

I don't grow "real onions" because I've had bad luck with them; they are likely to be puny and never bulb out or bolt (again, not bulbing out) under the conditions where I grow them.  

Dan Boone wrote:
I have been growing nondescript green onions from the grocery store, which in this climate seem to be perennial -- they persist and flower for several years without ever seeming to die back.  But they don't set seed, they don't multiply, and they aren't really an ideal crop, although I keep them around because they are completely idiot-proof, zero work, and any allium is better than none in hard times.   They grow about four feet tall, the green stems are pretty tough and fibrous (except for new growth), and the white part is leek-shaped and quite variable: some are tough and fibrous, some are tender and sweet like a fine shallot.  

That is so interesting.  A very different result than I had last time I started a bunch of supermarket green onions.  Mine turned into an awesome, perennial, multiplying crop that lasted for years and stood all winter.  Each plant would turn into about ten by the next year, with tons of leaf production.  They would flower too, but I just left those be.  I never dug them up, though - we only cut the green leaves which were all tender.  Maybe the white parts would have been different?  

Now in the desert, I started two new patches.  Hoping they are multipliers, too.  Hmm.  I guess I'll find out soon.

Good luck in your onion adventures!

I just found an additional source of potato onion bulbs: Peaceful Valley nursery also selling potato onions

I'm in the SW desert on very sandy clay.  Our shallots that were planted from bulbs are doing marvelously.  My little potato onion starts are tiny still.  I thought they might need shade and allowed a squash to grow over them, but that seems to have stunted their growth. The ones not shaded by squash are double the size.  I've uncovered them all now and will see what happens!  Gardening is such an experimental process.

If anyone finds more sources, please do post them in this thread.  Potato onions are a crop that could easily disappear if people stop growing them.  Knowledge can be completely lost in just one generation.  I learned about them initially, years ago, from the Territorial Seed Co catalog - and now they don't seem to carry them at all... *poof* one more source of knowledge gets lost.  

Thank goodness I only planted 1/2 my seeds because not one sprouted.  I wish I would have started them in pots instead of in the garden. Oh well I will try again in the Fall.  Good luck to everyone.

Kim Goodwin wrote:If anyone finds more sources, please do post them in this thread.  Potato onions are a crop that could easily disappear if people stop growing them.  Knowledge can be completely lost in just one generation.

Potato onions are the only kind I grow!

I know of two sources.

Southern Exposure Seed Exchange was mentioned by the OP, but I'll include it as a reminder. They ship September through November.

Sow True Seed is out of stock at present, but you can sign up to get an email notification when they're available again.

I have a yuuge crop of SESE (originally) potato onions. Several are seeding out. I am lazy and probably wont pick them until I have to, which is probably in the next month, but who knows.

I probably have somewhere around 80 lbs of these jokers.

I can make the seeds available on here, if they are of interest. I can probably talk a neighborhood kid into packing some bulbs and shipping them.

Thank you OP for an incredibly helpful, resource-full thread! I just bought some potato onion sets from Peaceful Valley on sale so I will be be mining all the links. I have Egyptian walking onions and bunching onions already but this will be my first time with potato onions.

Southern Exposure is a great resource for perennial alliums of all types.

I planted some in a raised bed and some in a swale and the ones in the raised bed fell over so I guess that means something.

Jen Fulkerson wrote:Thank goodness I only planted 1/2 my seeds because not one sprouted.  I wish I would have started them in pots instead of in the garden. Oh well I will try again in the Fall.  Good luck to everyone.

Do be aware that the seeds of alliums are notoriously short lived in storage - I actually saved seed from my own potato onions last fall (originally bought from territorial years back) and not a single one sprouted this spring. I think it was the lack of proper storage - they sat in a pail in the shed over the winter rather than being stored dry indoors :(  They stayed cool and dry, but it just wasn't good enough for such a delicate seed I think. Big failure there and I'll be trying again in a couple years.

Even the onion seed I purchase over the winter has a very low germination rate by the time we get to middle summer, which is messing up my attempts to start overwintering onions (established plants first thing in the spring would be a lot better than trying to race the summer solstice every year in this climate!)

Give them some extra time to sprout because older seed that's nearing its end of life is often weak/slow/erratic in germination. I have some onion seed planted in april just coming up now in a seed tray I replanted with lettuce and broccoli a few weeks ago.

Hi, I also grow potato onions that I bought several years ago from Maine Potato Lady.

Has anyone also grown dutch yellow shallots?  Are these the same as yellow potato onions or are they different?

Do people plant their potato onions in the fall or the spring?  I found that my fall planted potato onions have all gone to seed.  But the spring planted ones did not and I also got bigger bulbs.

I'm growing both potato onions (the standard yellow type) and Yellow Moon shallots. They are not the same thing.

I've been trying to get some of the new varieties that Kelly Winterton has found or created, such as Green Mountain Multiplier, Garnet Mountain, Dakota Gold, and others. I've had no luck finding bulbs for anything except the basic yellow potato onion and a couple of shallots.

Does anyone know where I can get bulbs of the newer, larger-bulbed potato onions that produce true seed more frequently?

Amazing post Kim, thank you!

On my farm in Missouri I had the SESE yellow ones and they did great. And I just ordered ones for here in Australia (So that is very helpful the post from Ais, thank you!) My question is, I feel I waste too much preparing them. Does anyone have any tips or tricks on wasting as little of them as possible? I save the skins and such for broth but I just thought maybe someone would have a trick to preparing them better than if they were a mini standard onion? Thanks!

I am currently planning to put in a fall garden, my first. We love onions, and these sound to be right up my alley! I plan to order some from Southern Exposure, since their Zone 7A is close to my 6A.

Just ordered some potato onion seed off of Etsy.  I was hoping to get bulbs, but they are rather pricey, if they don't take hold.  My Egyptian walking onions have thrived, despite some challenges, (lately, the chickens have discovered that raised bed, so time to fence it off!)  I'll be interested to see how they do!

Cathy James wrote:Does anyone know where I can get bulbs of the newer, larger-bulbed potato onions that produce true seed more frequently?

I have the dame problem,
I live in Belgium(Europe) and i can’t dementie find optatie onions. Let alone the larger bulbs.

Any tips?

Dan Boone wrote:
It seems to me [potato onions] might easily replace my "monster green onions" as a low-effort perennial allium that's closer to "real onions".

I don't grow "real onions" because I've had bad luck with them; they are likely to be puny and never bulb out or bolt (again, not bulbing out) under the conditions where I grow them.  

I've had the same frustrations with commercial bulbing onions. They'll grow, and I get onions, but they don't produce much relative to the space and effort required. And since I can't seem to successfully start them from seed indoors, I have been buying expensive transplants every year and having them shipped to me.

So it was time to try something different.

I grew some potato onions and yellow moon shallots this year, and was pleasantly surprised at how quickly they established themselves from bulbs and threw up strong green shoots. Their bulbs are not large, but I have read about a trick where you soak them in a 9:1 water/bleach mixture for 5-10 minutes before planting, which is supposed to kill some of the viruses in the bulb and produce much larger bulbs. I will try that next spring.

A couple of weeks ago I planted perennial bunching onion transplants (variously known as spring onions, Welsh onions,  Syboes, or Japanese bunching onions) and perennial I'itoi onions. The I'itoi are already sending up small green shoots. If they work out, they will form a dense bunch that I can separate and plant again. They are desert plants, so I don't know how well they'll do in New England winter. I'm hoping to have some in the outdoor garden, some in a cold frame, and a few inside under lights this winter. The Welsh onions are very hardy, so they'll be fine under mulch in outside beds.

A local friend has offered me some Egyptian walking onions, which I will try at some point.

I'm looking at a wide range of onions to find out what will produce the most food in the least space with the least work!

Faber vanmolkot wrote:
I have the same problem,
I live in Belgium (Europe) and I can’t [seem to] find [potato] onions. Let alone the larger bulbs.

Any tips?

I suggest asking around gardening clubs, and whatever European equivalent of the Seed Savers Exchange you have. Your best bet is to find an individual rather than a seed company.

I was unable to find a commercial source of I'itoi onions, but finally got some from an individual gardener.

Many countries restrict shipping onion bulbs across borders because of concerns about disease, so you will need to find a source inside the EU.

I never tried soaking my bulbs in the bleach water solution. I think I will try that when I plant mine out here, do you rinse them off after soaking them or plant them straight after soaking?

Best of luck with your new perennial onions, Cathy!

Billyray, those yellow dutch are great. They don’t keep well if they have wet weather right before harvest. I lost my seed that year. I found a clump this year that I didn’t know I had. It must have been tiny a few years ago. It came up in a strawberry bed and took care of itself. Hopefully I can get them started again.

Correction: I had the yellow potato onions from the Maine Potato Lady. They taste great. Lots flavor without being too strong.

Aimee Hall wrote:I never tried soaking my bulbs in the bleach water solution. I think I will try that when I plant mine out here, do you rinse them off after soaking them or plant them straight after soaking?

Best of luck with your new perennial onions, Cathy!

I didn't rinse them. But this is my first time trying this trick, so your mileage may vary.

I wonder if this might also increase the bulb size of I'itoi onions?

I'm wondering now whether to pull all the outdoor I'itoi at the first hard freeze, and let them dry in the house until spring. I have searched the net without finding any discussion of growing I'itoi in the cold regions that freeze hard. More experimenting is clearly needed.

I'm excited to find this thread. I just got my potato onions from SESE. Varieties? I didn't know, love all the links, I'll have to order more varieties and keep us in onions.

Potato onions (and garlic) don't like extended wet conditions - I lost several varieties to two back-to-back wet summers when they just rotted in the ground.  Those of you in drier climes should not experience this issue, but it was a problem here in the mid-Atlantic.

I want to try these, they look real yummy, where did you get bulbs or were they seeds

Using raised beds should solve the drainage problem. My back yard is sopping wet during spring, and there can be as much as an inch of water on top of the ground near the garden.

But it's not a problem because most of the garden grows in raised beds surrounded by boards, with excellent soil in the bed built up from compost, peat moss, and vermiculite. The water drains out of the bottom of the bed, leaving the soil moist but not wet.

I have been growing a potato onion that i got from ireland for several years now.
I am interested in trying to breed potato onions so i was looking for new varieties.
On ebay i found PO's from Paris and from Poland.
When i got them they looked just like my "irish" variety so i thought they may be the same variety.
I was so wrong.
I then managed to order 4 different varieties from a german seed saving organisation and they all look
like the first kind i got from ireland.
So the point is there are many, many different PO varieties out there that are brown/yellow/normal onion colour.
Also i found out there are hundreds of different potato onion heirlooms kept in european genebanks.
Most modern varieties circulating in america were bred by Kelly Winterton from seed of a spontaneous seed-setting of
his yellow potato onion variety and he used 2 other types too as far as i know.
The notion in america that potato onions were almost extinct is false.
They are not being grown much anymore but there still are many different varieties in european countries.

This text mentions 264 potato onion accessions, 80 of which turned out to be genetically identical to other accessions.
That still leaves over 150 genetically different PO's and the research didn't include all european countries.
So there still is huge genetic diversity.

https://www.researchgate.net/publication/344371500_Genetic_characterization_of_European_potato_onion_Allium_cepa_var_Aggregatum_G_Don_collections

Lots of images of european potato onion accessions:
https://sesto.nordgen.org/sesto/index.php?scp=ngb&thm=sesto&mod=&lev=tax&rec=37250&lst=img&offset=0

Tj Jefferson, could I purchase some potato onions for you?  If so, my direct email is: drchristy@simplyvibrant.com. Thanks for considering!

I will probably send a 20# box to someone on Permies who can dole them out as goodie bags. I won’t have them until summer since they are all planted at this point. I am doing the same with my landrace moschata seeds. If I have time  I will do bone sauce but that has gotten back burnered. Seeds I’m pretty reliable just because they are things I’m saving anyway.

I’ll post here when stuff is ready to go out.

Thanks TJ. I’m happy to help disperse them if you decide to share. I’m in the Santa Cruz mountains of Cali. I’m going to start some from seed as well and give ‘Em a go.

Phil,

Onions like raised beds, which drain well. If you are willing to create some raised beds, I think you'll find that even wet years are not a big problem.

"FullSkyFarm on Etsy sells bulbs and seeds from three varieties, including Green Mountain."

I have checked their offering periodically over a period of many months without ever seeing Green Mountain bulbs offered, only seeds. I would like to get some Green Mountain bulbs, which will be easy to start and breed true, rather than seeds, which are a pain to start and will be an F2 generation that doesn't breed true.

Have they stopped offering bulbs, or did they just have a year when supply didn't meet demand?

Does anyone know where I could get Green Mountain multiplier *bulbs*?  Or perhaps Dakota Red, or Dakota Gold?  I have been unable to find bulbs for sale for any of the varieties that Kelly Winterton created, despite a lot of looking online.