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daninthedirt

observation about onions bolting

daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
2 years ago
last modified: 2 years ago

My onions are a month or so away from harvest. I have about seventy 1015s, and about seventy Red Creoles, both short day onions. Interestingly, the Red Creoles are very interested in flowering. I've pulled twenty or so flower buds off of them. Not a single bud on my 1015s. One understands that onions tend to bolt when they are stressed, but the conditions have been identical for both varieties. Now, it is true that the Creoles are smaller onions, so the fact that they are planted a little closer together might make them more stressed, but ...

Is this well known, that some varieties are much more prone to bolting?

Comments (28)

  • robert567
    2 years ago

    From Dixondale site description...


    "Red Creole onions are small to medium in size with pungent red-purple flesh and tolerant to disease with very little bolt resistance, so planting these onions plants a bit later will decrease the number of bulbs that bolt."


  • farmerdill
    2 years ago

    Concur: resistance to bolting is a continuing goal of onion breeders. The older varieties are quite prone. There still is variance among modern varieties

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    Thank you. These are indeed from Dixondale. I usually grow both varieties, but I had not noticed this striking difference in previous years. How does planting later make them less likely to bolt? Is it a matter of stressors from cold weather that makes them want to bolt? Actually, it's getting pretty warm here right now.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago
    last modified: 2 years ago

    I guess I should ask, then, about the effects on the crop. Clearly, if you let the flowers bloom, the crop is toast, and the storage lifetime of any onions you manage to harvest is zilch. But if the buds are removed early and promptly, how seriously affected is the crop? As I said, this is my first year with such serious bolting.

  • farmerdill
    2 years ago

    pretty bad, catch the buds as they emerge, and the mature onion is still pretty good but will have that hard stalk into the middle. It cuts storage life significantly.. Common wisdom is to use the bolted onions first.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    OK, thanks. That's too bad. Red Creole are supposed to be my sorta "storage" onions. The lack of opportunities for good short day storage onions is a real handicap.

  • farmerdill
    2 years ago

    Just for information, I pulled Chiante in late May , hung them in groups of six from the rafters of a storage shed.. Ate the last St. Patrick's day. New storage record for me. Most of my varieties start sprouting in late December Winter was unusually dry this year, Don't whether to credit variety or low humidity. maybe a little of both.


  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago
    last modified: 2 years ago

    Nice. So they stored almost a year for you? Yes, I harvest in May and most of mine are sprouting by December. Twillyseed says Chiante F1 "ships and stores well". That may be worth a try next year.

    Uh, on second thought, what Twilly also says about them is "Good for short to mid range storage, 2-4 months."

  • beesneeds
    2 years ago

    I've had onions bolt differently too. I just figured it was like hardneck garlic does and always treated it like scapes to pinch out early instead of let get big enough to eat. Like the flowering takes away from how much bulb I get.

    This year I'm starting to tinker with some 'perpetual' onoins, the kind you want to let cluster and divide over time. I hadn't thought about what about them blossoming till now.

  • John D Zn6a PIT Pa
    2 years ago

    Some onions go to seed (bolt) in the first year and others in 2 years. If I were growing onions for seed the one year varieties would be great. Seems like if you're growing onions for bulbs the 2 year variety would be preferred. I took some Copra bulbs that had sprouted last spring and buried them in the ground and I got seeds off them which I plan to direct seed into the garden. It's a hybrid, so we'll see what I get.

    As stated above though; short day onions don't have a lot of choices.

  • LoneJack Zn 6a, KC
    2 years ago
    last modified: 2 years ago

    Over the years I've noticed that the thicker starts from DD tend to bolt more than the thinner ones do. The last few years I've planted the thickest starts towards the ends of the rows if I have to plant them at all and it has confirmed my suspicion.

    Did the Red Creoles tend to be larger starts than the 1015Y? My bunch of Red Zeppelin starts from DD were quite large this year and I expect a lot of bolting.

    I segregate the bolted plants at harvest and dehydrate for making powder or freeze them for use over the winter. Not a total waste.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago
    last modified: 2 years ago

    I don't recall whether my Red Creole starts were larger or smaller than my 1015 starts. That's an interesting finding, and worth remembering. When I'm planting starts, the larger ones tend look more favorable. At this point it's a little hard to segregate the bolted plants, because I never took the trouble to flag them after pulling off the buds. I have to say that I do remember last year I was a little disappointed in the storage lifetime of my Red Creoles. They started to sprout maybe only a month after the 1015s. Maybe I should suppose that those were onions that bolted? The last ones held out a month or two more, until December (harvest in May), which isn't bad.

    Yes, I'd like to hope that onion breeders work a little harder on developing short day storage onions. It is a little exasperating that while Red Creoles are the closest one can get to storage onions in a short day variety, the fact that they like to bolt just kills that option.

    I'm not sure why I'd be growing 2-year onions. I grow onions for onions. Not bulbs.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago
    last modified: 2 years ago

    No, storage onions are simply onions that can be stored a long time. As in, six months or more, with out refrigeration or ethylene. As in, full-sized edible onions. I don't plant bulbs. That's simply not true that seed-grown onions in their first year don't flower. I've grown onions from seeds to make starts and yes, sometimes they try to flower several months after planting out. You'd rather they didn't. But sometimes they do. That's what "bolting " is, and that's what we're talking about here. Bolting is specifically premature flowering, and for second year onions, flowering isn't premature.

    That does make some sense that exposure to low temperatures could induce onions to bolt. But last year we had a viciously unseasonable freeze in February. I covered my onions, but they were probably exposed to 10F, and I didn't get much bolting.

  • beesneeds
    2 years ago

    Yes, full sized edible onions are bulbs. Storage onions are grown for their bulbs. Alliums aren't tubers or rhizomes. They are bulbs, those onion layers are modified leaves. Garlic and leeks are bulbs too. Onion sets are little round bulbs that have had full dormancy and are in second year. Onion starts are young elongate bulbs that haven't started filling out yet. Sometimes starts get treated to fool it into dormancy to cause a 2nd year reaction. It shouldn't happen with first year from seed and kept live starts unless they undergo a garden situation which can trick their dormancy thing and make them think they are in their second year. Not actual full dormancy like sets, but the partial dormancy like starts that have been treated for dry shipping. In a garden situation this can come sometimes with watering issues or temp fluxes. The plant might be in the same season to us humans, but the plant thinks it's in it's second year- and bolts.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    OK, when people talk about planting bulbs, they talk about the tiny ones. I call them bulblets. Those are not formally called "storage onions", though I'd have to assume that they last a long time. It is true that planting bulblets instead of planting small plants is more likely to result in bolting. Maybe because those bulblets think they're on their second season.

  • beesneeds
    2 years ago

    Bulbets (AKA bulbis) aren't sets- sets are the tiny bulbs people plant. Sets are full 2nd year onions grown from seed. Bulbets are produced often by walking or tree onions, and can be produced by other alliums in their second year cycle. Bulbets are best used in their first year fresh like seeds for planting. They also can store well and be eaten. Some folks that like to let their hardneck garlic go to scape or let past scape sometimes find bulbis formations in the stems- I find them quite tasty as a soya pickle. Bulbets aren't popular for planting, and I don't think I've ever seen them for sale for planting. I have seen a lot of seed, sets, dryroot starts and live starts.

    There is also an additional confusion on this one sometimes. Bulbets are sometimes referred to as sets or topsets. But topsetting onions tend to still be sold by the plants or bulbs.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    That's helpful. I've just always called "sets" bulblets, since many people mistakenly call small plants sets.

  • beesneeds
    2 years ago

    Sets are small dormant plants- they just haven't started leafing out yet. A lot of people do call small plants sets, or the small plants growing from sets as sets. Like instead of saying they planted onions from sets, they say they are growing onion sets even though they are already small plants by then. Sometimes people call starts sets, particularly when they are dry root starts- but they really are just starts from first year seed, not sets as second year bulbs. I've seen few week old seedlings referred to as sets too and I'm not sure why- maybe because they set them in the ground? They aren't mature enough yet to be starts and for sure aren't sets.

  • kevin9408
    2 years ago

    Sorry about your onions Dan. Last year I lost my onions because of a watering problem and they withered away. A few weeks later it rained and the onions started growing again but why and what stage were they in? They were in the bulb development stage and would never get bigger and eventually flower if given the time so I tilled them in. It was the first time I had to buy onions in 16 years.


    I would say your plants bolted because of water stress or a cold snap when your plants were in the bulb development stage and no other reason, and If the stress would of happened while the plants was in the vegetative stage the bolting would never happen. The tolerance level to stress between the two cultivars is probably different and why the 1015 hasn't bolted.

    Starts, (the plants you received from DD are starts, but they call them plant bunches.) are onions which are still in their vegetative stage and will grow through a cold snap or a watering issue but will never bolt if the stress is removed before the photoperiod triggered the bulbing stage, (only smaller onions) . If the onion bulb was bigger than the neck, like twice the neck size, and bulb initiation started it could trigger bolting but DD knows how to grow sets right, so I don't believe the starts was the problem. (They didn't have bigger bulbs than the neck, right?)

    Sets (small dry bulbs) are technically 2 year onions and I rarely plant them. Bolting and low storage is a problem so If I do use sets I pick the smallest bulbs from the bucket and no bigger than a dime.



  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    There was no water stress, and while it has been a cool spring, the last freeze was two months ago. Long before bulbing. It's been warm for the last month. Actually, while the 1015s are bulbing like crazy, the Red Creoles have barely started. But I've been picking buds off of them for weeks, long before any sign of bulb development. The starts had NO bulbs.

  • kevin9408
    2 years ago

    "the 1015s are bulbing like crazy, the Red Creoles have barely started." That is Odd. Could there be a possibility the Dixie dale worker pulled the Creoles from the wrong bin and you got a long day cultivar? Right now your area has about 12 1/2 hours of daylight so they should be bigger then barely.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    As I remember, the same thing happened in the last two years. Red Creoles are just slow for me.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    I have some more info sent to me from Dixondale. Bolting can happen in response to cold weather stress. With temps below 45F, the onions will go dormant, and when they warm up, they wake up, and it's a new season! That's why planting later can help avoid bolting. We've had, in fact, a cool spring, with temps easily going below 45F. Interestingly, one of the hazards of pulling off a bud on the seed stalk is that you leave an open shoot that water can flow down into, straight to the bulb core. It's that water that can rot the center of the bulb. But it's very clear that the risk of bolting is higher for some varieties. Interestingly my crop of Red Creoles were popping out seed stalks several times a day for a week or so. That has entirely stopped.

  • beesneeds
    2 years ago

    Ok, so Dixondale has confirmed what I was saying before. Your starts got tricked into thinking they were second year plants, and so they bolt.

  • robert567
    2 years ago

    They are sort of second year plants. The seeds were started last Summer, then starts replanted in Autumn, then Winter happened (mild in his area), then Spring. It is natural for them to bolt when it warms up, but as Farmerdill said onions have been bred to be grown this way in lower latitudes and resist bolting.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    It is indeed species specific. The 1015s don't bolt AT ALL. Maybe only a quarter of the Red Creoles did. So there isn't a hard and fast rule. It's mainly bad luck.

  • daninthedirt (USDA 9a, HZ9, CentTX, Sunset z30, Cfa)
    Original Author
    2 years ago

    I should add that, in answer to a question I posed to them about it, Dixondale says that they actually do have some ongoing studies to breed short day storage onions. Let's hope for their success!