Experiments with onions

VermontCathy Posts: 1,991 ✭✭✭✭✭

After growing bulbing onions for several years and being very dissatisfied with the size of the bulbs and the yield, last year I decided to try different types of onions to find something that would be easier and more productive to grow here.

So far I have been grown:

  • Walking onions
  • Potato onions & shallots
  • Syboe onions (Scottish scallions)
  • I'itoi onions (from the Desert Southwest of the USA)

All four of these successfully grew in my 2020 garden. All of them are expected to be perennial, though I don't know until spring whether Syboe and I'itoi can survive a Vermont winter under mulch and snow.

Because most of these types of onions are not from New England, I am trying different methods to see what it takes to get them to survive and prosper.

Walking onions

  • These were given to me a neighbor. They are thought to be the oldest type of onion, the closest to wild onions, and very hardy. They are almost weeds, so I know they'll survive.
  • In 2021, I will transplant some to my unimproved clay soil and see if they can grow in that. If so, it will free up space in my beds.

Potato onions and shallots

  • These two are closely related, so I lump them together. They are both multiplier onions that start from a single bulb and grow into a cluster of many. The next year, you separate the bulbs in the cluster, eat some, and replant some.
  • I planted some in the fall of 2020 and brought some inside for the winter, with plans to plant them in the spring of 2021. Both planting times have been reported to work, but I will find out which one works better for me. Last year I bought them in the spring and planted them immediately, and they were quite productive.
  • There have also been reports that the small bulbs can get much larger, perhaps 3X the size, if soaked in a 9:1 water/bleach mixture before planting. This is supposed to reduce the virus load that the bulbs carry and allow them to grow better. I did not do this with my spring 2020 crop, but the fall 2020 and spring 2021 crops will both be soaked.

Syboe onions

  • These hardy green onions, also called spring onions, are very similar to the scallions you purchase in the grocery store. They don't grow much of a bulb, but the greens are tasty.
  • I expect these to easily survive the winter in the beds under leaf mulch and snow, but I transplanted a few to the cold frames just in case.

I'itoi onions

  • This type of onion is quite rare. I searched the web for it for months before finding a backyard gardener who provided a few. Few commercial operations offer them, and since the I'itoi are a Desert Southwest plant, no one local had any. They have very small bulbs, but under good conditions will multiply into huge cluster of plants.
  • I received them in mid-summer, transplanted them, and they immediately began growing well. You can carefully cut off the stalk, use it as a green onion, and it will not only grow back but be encouraged to divide into more onions. They survive droughts extremely well and will begin growing again when water returns.
  • I'itoi present the biggest challenges and the greatest chance of failure, because my climate is very different from the Desert Southwest. And because they are so hard to obtain, if I lose all of them, I may not be able to get more. I don't have enough to eat them yet, though I've tasted a few shoots and found them good. Hopefully 2021 will produce a bumper crop so I can replant some, eat some, and give some away to local gardening friends. Wouldn't it be great to get these established in Vermont gardens?
  • So I am experimenting with four different ways to propagate them: leaving them in the ground all winter under mulch and snow; leaving them in cold frames; harvesting them, letting them dry out, and storing them inside for replanting in spring; and growing them all winter inside in pots under lights. This gives me the best chance that at least one method will work well.
  • It's too soon to test the first three methods, but I have been growing a couple of them all winter on my grow light shelf. Occasionally I will clip one back, peel away the dry skin that makes it hard for the green shoot to break through, and watch it grow back. An online video claimed that cutting them back carefully triggers bulb division, and my own experiments suggest that may be true. I started with two in the pot at the beginning of winter, and while one died, the other one has become four, and a fifth is about ready to be separated and planted on its own.

What experiments have you done with fruits or vegetables that you wanted to grow? There are many vegetables and fruits out there that have not been tried in every climate, and some rare varieties (like the I'itoi) have almost no information availble on the Internet.


  • silvertipgrizz
    silvertipgrizz Posts: 1,990 ✭✭✭✭✭

    @VermontCathy This might help some:

    I know it says fall here but keep reading.

    Also, got any tips on the egyptian onions? I got some for the first time a few months ago and will be my first time planting..in the next day or two when it's supposed to dump snow on us..

  • Monek Marie
    Monek Marie Posts: 3,542 ✭✭✭✭✭
    edited February 2021

    @silvertipgrizz Egyptian onions are very hardy. As long as the soil can be worked they will be fine. Since you know its going to snow put a mulch on the soil and they should be fine. You can also wait a few days. Egyptian onions will regrow during a season a spread so there is not real "have to plant "date. Love this plant. It's edible in all stages too. I use the smaller onions on top (after I save some to replant) to pickle and I will stuff the stem and steam them. If managed properly you can supply the entire area with egyptian onions

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    @silvertipgrizz Denise Grant is right; Egyptian onions (walking onions) are very hardy and you really can't go wrong with them. Personally, I would wait until the snow is gone, then plant them as soon as the ground can be worked, but snow certainly isn't going to kill them.

    If only commercial-type large-bulb onions were that easy!

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭


    From the article: "Our grower has had excellent results in almost all regions of the US. The exceptions are south Florida, south Texas and the extreme northern states bordering Canada. Even parts of Maine have been able to grow good sweet onions in the fall!"

    Hmm, "extreme northern states bordering Canada" sounds very familiar. :-) We only have about 120 days from last frost to first frost, so the only things that can be planted in fall are those that will overwinter and then resprout in the spring. That includes multiplier onions, shallots, garlic, strawberries, kale, and some varieties of cabbage.

    From the article: "Winter temperatures down to the early 20’s won’t damage onions if mulched and protected."

    Right now it's 17F (-8C), and tonight we are expecting 1F (-17C). Fortunately, some onions and garlic can readily deal with these temperatures under the mulch and snow.

  • silvertipgrizz
    silvertipgrizz Posts: 1,990 ✭✭✭✭✭

    @VermontCathy Don't forget your bubble wrap window covers, warm robe, slippers and some fresh off the stove hot chocolate witha pinch of 'red pepper' and a piece of peppermint stick...

    Do you understand 'long day/short day/intermediate day'? If not I have an article that might help..it helped me and that was last week when I bought some 'candy onion sets' .. finally makes sense.

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    @silvertipgrizz Here at almost 45 degrees north, we are solidly in the "long-day" zone. Long-day onions can do well here, but intermediate-day would be questionable and short-day wouldn't work well at all.

    I have successfully grown long-day onions from transplants, but they don't do as well as I would like. I wanted "lunkers", onions with large bulbs that are easy to slice for sandwiches. Instead, my largest bulbs were only about 2" across. And buying transplants is more expensive than buying seeds.

    Steve Solomon's excellent book _Gardening When It Counts_ goes into great detail about exactly what is needed for each of a wide variety of vegetable types. He ranks them into "easiest", "harder", and "difficult". Multiplier onions and walking onions are rated "harder" (i.e., moderate), and bulbing onions "difficult". His very first statement in the "Onions, bulbing" section at the beginning of the "Difficult vegetables" grouping is, "Let me warn you in advance. This section is complex because I am not a Pollyanna garden writer." He goes on to talk about mildew-like diseases, day length, bolting to seedstalks, and so on. And because they are biennials, it's not easy for a small gardener to save his own bulbing onion seed.

    On the other hand, the multiplier onions I grow get nearly as big as my bulbing onions, and take no effort at all. Their stalks are thick and healthy instead of thin and dried-out. They will cost nothing to propagate now that I have them started, because every year I save some bulbs to replant, just like garlic. It doesn't require 2 years to produce seed, because I am not producing true seed, but planting the actual bulbs.

    Multiplier onions used to be extremely common on homesteads, in kitchen gardens, and other small-scale plots. You can see why. But with the rise of commercial farming and the decline of home gardening, potato onions almost disappeared and became very hard to even find. Fortunately, there has been a recent revival of interest in potato onions, so they are gradually becoming more widespread. i gave some to two local friends, and I hope that both will propagate them and spread them further!

  • Torey
    Torey Posts: 5,690 admin

    Walking onions are hardy enough to survive my winter temps that can get to -40 (F &C). I have a short frost free season, 90 - 100 days if we are lucky. But I can still get up to 3 crops of top bulblets in a year. Bulblets will have bulblets which, in turn, have more bulblets.

    A lot of mine go into soup stocks but some go into pickles.

    Multipliers aren't quite so hardy in my garden. Some will survive the winter but not all years. Some winters they will all die. Same with Shallots.

    I buy my regular onions from local farms as I just don't have any luck with them. They seem to get attacked by onion fly in my garden.

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    Most people seem to plant multipliers in spring. However, some varieties of potato onion keep so poorly over the winter that they must be planted in fall or lose viability.

    I'm trying both to see what works best, which may be different in different regions, or depend on exactly which multiplier you are growing.

  • Monek Marie
    Monek Marie Posts: 3,542 ✭✭✭✭✭

    I love this info!~

    Onions are so good for you that I grow a lot

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    @torey "Multipliers aren't quite so hardy in my garden. Some will survive the winter but not all years. Some winters they will all die."

    You could probably harvest them in fall, store them in a cold cellar or closet, and replant in spring.

    Yellow potato onions store fairly well for spring planting, but white and red ones don't keep and usually must be fall-planted.

  • Torey
    Torey Posts: 5,690 admin

    @VermontCathy Another chore to add to fall clean-up! I have never had much success at storing roots or bulbs over the winter. But maybe I will try again this coming year.

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    @torey When you say you haven't had much success, what do you mean? Do the roots or bulbs rot, develop mildew, or just refuse to sprout next spring? Do you lack space to store them? Or do you just end up eating them over the winter? :-)

  • Torey
    Torey Posts: 5,690 admin

    @VermontCathy When I leave multipliers in the garden, there are several things that might happen. Sometimes they rot. Sometimes they just refuse to sprout. Sometimes it looks as though something has eaten or otherwise disturbed them. The deer seem to like playing in my garden. Even if it is something that they won't eat, they will still put things up.

    I'm not very good about digging things up and bringing them inside. I tend to get busy with other things and don't get back to caring for the roots or bulbs after the drying process. I don't have much room where it is cool but not freezing so storage space is an issue. So I always avoid things like dahlias or glads that have to be dug up and overwintered inside. I might be getting a root cellar this year and that would certainly increase my storage capabilities.

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    Update: my walking onions easily made it through the winter under mulch and snow. I'm not surprised, as these came from a local gardening friend, and I don't think she digs them up before winter.

    The Syboes were hit a little harder, but I think they will make it through, even without being in a cold frame.

    It's hard to tell how the potato onions and shallots are doing. We'll see as we move forward into spring. I have plenty more in the house that will be spring-planted, even if I lose all of the fall-planted ones. But I believe most will survive.

    The I'itoi are the toughest. So far, it looks like I have lost not only the ones in the open garden under mulch, but all of the ones in the cold frames as well. That is a big setback, as I only have a few in the house either grown under lights during winter, or dried and stored last fall and kept in the cool basement through the winter. But it's not too surprising since they are adapted to the Desert Southwest, not New England.

    I will replant the I'itoi outside only after last frost is past, because these are hard to get and I don't want to risk losing the remaining few. The good news is that they multiply quickly, so I may be able to replace the losses in a single growing season. This fall I will pull all of my I'itoi and keep them in the house all winter. It's probably going to be harder to get my local gardening friends interested in an onion crop that is a bit fragile in our climate.

  • MissPatricia
    MissPatricia Posts: 318 ✭✭✭

    Thank you VermontCathy. I have grown Egyptian walking onions and shallots, but just had never heard them called multiplier onions though it is an apt term. Potato onions? I never had heard of them either and still don't know. Here in Alabama, I leave walking onions in the ground year-round. I am not sure how big they are supposed to get, but I plan to fertilize them this year and see what I get. Mine were really small.

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    @MissPatricia "Multiplier onions" are not a specific type of onion, but a catch-all term for onions that reproduce by dividing into clumps, each of which forms its own bulb. Potato onions, shallots, and walking onions are all types of multiplier onion.

    "Potato onions" are closely related to shallots, but slightly larger than most shallots. I'm not sure there is a consensus on whether potato onions should just be regarded as a type of shallot, or if potato onions and shallots are closely related but distinct.

    For gardeners, rather than botanists, it doesn't really matter. You can use them interchangably. But since potato onions are usually larger, it's worth seeking them out.

    Pretty much all multiplier onions are smaller than the huge "lunker" commercial bulbing onions you find in the grocery store, but it is extremely difficult to grow those huge onions in your home garden. It is much easier to grow larger numbers of small onions than small numbers of huge onions. ("Lunker" is not a specific variety of onion, but a word that means "really large onion bulb".)

    There is lots of information on potato onions here: https://docs.google.com/document/d/1tlnAG6epHBAd4SLOA4zlHa3EnA7r0OaZy6NpNUpIgHA/edit

    A good video on potato onions can be seen here: https://www.youtube.com/watch?v=psubmZh9fSw

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    I went to plant the I'itoi onion bulbs that were allowed to dry out and be stored in a paper towel in the basement all winter.

    I was surprised to find that when I removed the outer skin from a couple of them, there was no real bulb underneath. The tiny root base and bone dry skin above was all that remained.

    With most plants I would conclude they were dead and compost them, but these onions are adapted to the Desert Southwest and extremely drought tolerant. I've read stories of I'itoi bulbs being stored in a desk drawer looking completely dead, yet producing a good crop when planted.

    So I planted them today. We will see what happens.

    I have about eight healthy I'itoi plants grown indoors under lights last winter. I started hardening them off today, and will plant most of them outdoors soon, keeping a couple growing in the basement just in case.

  • jowitt.europe
    jowitt.europe Posts: 1,467 admin

    Walking onions are really robust. I do not bother digging them out or covering. They do survive our cold winters and develop delicious leaves as soon as the snow melts and they get some warmth. They are one of the first green one can get after winter here.

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    In a cold climate like Vermont, I would rate onion varieties in descending order of robustness like this:

    1) Walking onions

    2) Potato onions or scallions

    3) Syboe or spring onions (scallions, no bulb)

    4) I'itoi

    In a hot desert climate, the order would be different, with I'itoi at or near the top.

  • VermontCathy
    VermontCathy Posts: 1,991 ✭✭✭✭✭

    I harvested my onions yesterday. There were a lot of walking onions, and a crazy large number of potato onions and shallots. The garage floor now has a lot of onions on newspaper on the floor, drying out for storage.

    Soaking the bulbs in 9:1 water/bleach solution for 5-10 minutes before planting worked very well. The bulbs are significantly bigger than last year. I will do this every year from now on.