MOFishin
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Growing Onions from Seed - When to Start?

I've been researching this the last couple of days, and my head is kind of spinning. I'm in zone 6A. It sounds like intermediate onions would be my best bet. But do I start my seeds in Spring or Fall? Indoors or directly sown in the ground? Could I start some now and have them ready to eat before our first frost, which I believe is usually late October?
I've read so many things, I'm not sure what to do. I was thinking of going with red onions, if that makes a difference.
Thanks.
Oh, I almost forgot. One thing I read is to have them at "cool room temperature" when starting indoors. So, I'm assuming my heat mat won't be necessary?

Peter1142
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Where exactly are you located? That will determine which type of onion to grow.

Onions are started indoors in winter for planting in very early Spring, in Northern and intermediate zones. They will not form bulbs in the Fall, the day lengths are too short. But you can get nice green onions!

They definitely do not need a heat mat.

You can also buy starter plants in the Spring and grow that way, or plant sets which IME are prone to bolting and not making good bulbs.

MOFishin
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Thanks. I'm about 20 miles north of I-70 in MO. North of Columbia, MO to be more specific. Zone 6A according to the hardiness zone maps I've looked at.

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jal_ut
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You will likely need short day onions. Plant sets early February for large onions.
If you want green onions plant seed. .

Taiji
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I heard lots of good things about the onion variety "Candy" this year, so got some seed from an ebay vendor. I started some in a flat around February or March I think. I probably would have started them earlier, but didn't really get the idea to do it till I got excited about that variety. I set them out later, and it looks likes they are going to do well. I believe they are starting to bulb up nicely. It is an intermediate variety which is probably good for your area, but they say it is one of the few onions that does well almost everywhere. I'll be anxious to see what happens. Definitely the healthiest strongest tallest onions I' ve ever grown so I'm expecting great things! Candy is not a red onion, by the way.

It's probably too late now to start some from seed to get winter storage size onions, but you could start some seed maybe, and get some green onions like Jal said. I don't know if you can still find some onions sets this late. Last year I did find some late in the year at a discount from one of the big box stores. They still did fine for green onions.

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rainbowgardener
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I haven't grown onions since the big move, except green onions. But I used to be in zone 6b. I grew onions from seed by planting them in the fall. They would sprout a little bit and then go dormant for the winter and over-winter. Then in late winter they would start growing again and be bulbed up by sometime in mid summer.

I also grew the Candy onions from sets planted in early spring. They worked out very well for me.

Peter1142
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Columbia MO is 39 degrees latitude and is NOT short day. Borderline Intermediate / Long Day.

If you go to my blog linked below my journal for growing onions and leeks from seed this year is there. They are doing great and bulbing up now, the reds are just about ready.

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Onion seeds in the fall. That's interesting. Maybe I'll give that a try.

MOFishin
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Thanks everyone.
Peter1142 wrote:Columbia MO is 39 degrees latitude and is NOT short day. Borderline Intermediate / Long Day.

If you go to my blog linked below my journal for growing onions and leeks from seed this year is there. They are doing great and bulbing up now, the reds are just about ready.
That's what I was thinking Peter. I think I'm going to try intermediate first, and then maybe try long day. I'm checking out the blog now.

Peter1142
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I think you are more intermediate. Good seed companies list the specific adapted latitudes for each variety. I do know someone who grows Candy in your area.

MOFishin
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Peter1142 wrote:I think you are more intermediate. Good seed companies list the specific adapted latitudes for each variety. I do know someone who grows Candy in your area.
Interesting. That will probably be the route I go.

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Dixondale farms is a good source of onions and they have a good tutorial. Long day onions are grown above the 36th parallel and short day onions below it. Intermediate somewhere inbetween the two. It depends on you day length
If you have at least 14-16 hour day lengths = northern varieties
12-14 hour day lengths = intermediate
10-12 hour days = short days.

The closer you get to the equator the shorter the days get.

When planting from seed where days are short. Planting should be done in September or October. Later than that, it may get too cold before the tops have a chance to grow or the plants will bolt in spring and reduce bulb size. This is what happened to me this year. My onions bolteed and went to seed and produced very small bulbs.

https://simpson.ca.uky.edu/files/an_ipm ... _in_ky.pdf
https://aggie-horticulture.tamu.edu/arch ... ONGRO.html

Peter1142
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39 degrees latitude is definitely borderline for long day onions. Many varieties are adapted for 40-43 degrees plus. If you go to Johnny's Selected Seeds for instance the exact latitudes are listed for each variety. I am at 42 degrees and there are many long day varieties that don't work for me. OP is not short day so this doesn't apply to him.

In the end categorizing onions like this is for our convenience not theirs, and every variety is different, and the day length requirements are not just a specific longest day length but how long it occurs for in combination with high temperatures.

I definitely agree with Dixondale, getting onion plants from them is a great way to try for a first time growing.

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rainbowgardener
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That's why the Candy onions did so well. They are intermediate day and are more flexible in their requirements.

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jal_ut
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"Onion seeds in the fall. That's interesting. Maybe I'll give that a try."

Might work there. Doesn't work here. If the ground freezes you lose them.

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rainbowgardener
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Dunno.... I did this in Cincinnati where ground definitely freezes. Everyone's experience is different.

Peter1142
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It's certainly possible to overwinter some onion varieties in the long/intermediate day areas, depending on how cold it gets, but this is not traditional practice. Onions exposed to cold can bolt the next year, ruining the crop, or straight up die, they are not bred for this like short day varieties. I did see Johnny's selling a variety "bridger" bred for this purpose.

Growing onions as a fall crop to bulb up in the fall is another story, this simply isn't going to work, by any conventional wisdom at least, as the day lengths and temperatures aren't there. If you are able to do it by all means please fully document the experience including variety and planting dates.

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applestar
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Subject: Trying Onion Sets.. in my area?
applestar wrote:Wow you are pretty far north according to Wiki
Location of Labrador City in Labrador
Coordinates: 52°57′N 66°55′W
Country Canada
Province Newfoundland and Labrador
Although typically, onion sets are said to be ready to plant about one month to 6 weeks before last average frost once the ground has thawed, you may want to consider seriously freeze hardy varieties. At first glance you seem to have chosen ones that are popular in UK, and that would be good in terms of latitude and day length -- and you must have some really long days during the summer! --but most of UK's lowest temperature climate can be comparatively milder than where you are, I think?

What you would need to watch out for is killing freeze that could wipe out bulb onions. According this, Walla Walla variety and most potato/multiplier onions are hardiest and can survive down to 5°F (-15°C):

https://www.slideshare.net/SustainableMa ... wling-2013

Besides Walla Walla which is the only one I had heard about, Candy and Bridger are also killing freeze hardy varieties, according to this article:

Plant onions for overwintering now - The Washington Post

https://www.washingtonpost.com/lifestyl ... story.html

I can understand your wanting to save the greenhouse and cloche covered space, but you may still want to give them some protection with simple hoops and row covers?

That's about all I can think of. You must face some really challenging conditions. :shock: Hopefully other members from similar climate will contribute. :-()

imafan26
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I can't really grow from sets. They are not available here and it is very hard to find any company willing to send live plants except for bareroot roses to Hawaii, so I have to start from seed. I grow Texas granex which is the same as the Maui Sweet onions. It is not just zone that is important but also microclimate. Like the Vidalia onions or Maui onions here, just planting that variety does not guarantee a good result. The seed is one thing but the soil, temperature, elevation, light, and water have to be just right.

The commercial onions here grow in Kula which is at a high elevation on the slopes of Haleakala in volcanic soil. It gets a lot of sun and it is much cooler there. The seed is from Texas a small Pecos onion variety. It is very sweet because it is low in sulfur and has a high water content. The down side is that it does not keep very long. The best planting date for onions here is October 15.

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jal_ut
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The Egyptian Walking Onion is worth a look. ( other names: Top setting Onion, Tree onion.)

Taiji
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Besides my Candy seeds I also planted some Texas Granex plants that I got in a bundle from a big box store. They were old and didn't look too healthy and marked down in price, but thought I'd give them a try; they hardly cost anything. Didn't think they were doing too well; I didn't give them much attention. But, the other day I pulled one since the tops are starting to fall over. I was so surprised to get a decent onion, fairly large.
The store had some long day varieties too that they shouldn't even be selling around here, but you know how the big box stores are! Thanks to what I've learned on this forum I chose the short day granex!

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Some of the Texas Granex onions have sent up a flower stalk. I think it's because they were neglected for so long, or stressful weather or whatever. But, I was wondering if I save the seeds and plant them next year, will I get a true variety? Also, if I cut the flowers off now while they're blooming will the seeds be fully formed or do I need to wait until they're all done? I was afraid if I wait too long the seeds might all fall onto the ground and be lost.

( I noticed the insects really like the onion blooms) I actually saw a tarantula hawk on one today. :) wasps too.

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jal_ut
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It is not unusual for onions started from sets to send up a flower stalk. That is after all the plants mission, to reproduce. When you see these flower buds, just clip them off with about six inches of the stem. You can use these buds for eating or flavoring same as you would use an onion.

About the seeds, you will need to leave the flower cluster on long enough for the seeds to get fully ready. Don't yank them too soon.

Peter1142
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That's why I don't grow sets.

The onions that have sent up a stalk will not store well, and often don't make a harvestable bulb at all.

Taiji
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Yes, I've noticed my Candy onions I did from seed are doing great and not showing any signs of sending up a stalk. I thought if I save some Granex seeds for next year maybe they'll do the same.

I only bought the granex plants on a whim and thought I'd see what happened. Though some have gone to seed, I am getting a lot of good onions too. Thx for the info! :)

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Yes, you don't want to save seeds from bolters.

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jal_ut
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If I plant sets in the Spring I get this:

Image

If I plant seed in the spring I will get some onions the size of a walnut.

Peter1142
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No one said anything about planting seed (directly). I am talking about starting transplants indoors or buy transplants. You can often get them at garden centers, or buy directly from Dixondale. They have much less propensity for bolting. I have done it all 3 ways and will never plant sets again. I have onions like that this year from seed started indoors in January. But, hey, whatever you are happy with.

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rainbowgardener
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I sort of thought planting onion seed in the fall was they way it was conventionally done. We always plant garlic cloves in the fall to sprout and then over winter and they are all alliums.

Peter1142
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That's how it is done with short-day onions down South. Not here up North. They don't survive the winter, and can bolt if they do survive. Onions are not garlic... they are very different.

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jal_ut
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Garlic will overwinter here. Onions will not. Here we can get onion sets from the local garden store and plant sets in the Spring.

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applestar
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I need to do a systematic dedicated experiment --

It turns out that Candy is one of overwinter-able varieties. Being a day-neutral intermediate, this is probably still your best choice,@ Rainbowgardener. :wink:

I've casually tried sowing Walla Walla in the fall and covering the row with plastic low tunnel. The ones at the sturdiest double-layered end didn't make it, but the ones that came undone and flappy did. :? I might have some WW seeds left but if I'm going to compare, I probably should get fresh seeds....

I'd like to try Bridger too but availability seems to be limited to Johnny's and I'm not sure I can afford their high seed price out of my rapidly dwindling gardening budget. But Bridger seems to be the MOST winter hardy, according to descriptions.

I could probably pick up Candy seeds at a more reasonable cost... But my location seems to be at northern edge of intermediate onion growing areas.

I have to decide soon -- I need to start them in August according to one source.

Peter1142
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I was excited to grow bridger, until I realized it will not bulb up until the long days of summer just like any other onion, offering only the convenience of not growing starts, at the loss of a good variety of selections... looks like a pretty generic onion.

Walla Walla is a very nice onion... I might try overwintering some. I didn't realize it was hardy, thanks for sharing.

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Peter1142 wrote:Yes, you don't want to save seeds from bolters.
I was thinking that too; that if I start plants from those seeds they might produce plants with the propensity to go to seed early also. And yet, somebody somewhere along the line had to get their plants to go to seed to get the seeds. Maybe some controlled environment forces the plants to produce seeds on purpose?

Just to be sure I'm on the same page with everyone else, when one talks of sets, you mean the actual plants that come in bundles that look like little green onions, or do you mean the little bulbs that come in the net bags? Or are the little plants in bundles called plants and not sets? (I think we're all in agreement as to what seeds are)! :wink:

Peter, I noticed in your onion photos you trimmed your greens back. Does that help, and do you do that only once?

Peter1142
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They produce seed in a normal two year cycle...at least I would assume so. It is not bolting when they go to seed after doing what they are supposed to do.

Sets are the tiny bulbs that come in a bag. The green plants in bundles are transplants.. not sets.

I trimmed the foliage frequently, before transplanting... honestly I am not sure if it made much of a difference.

Taiji
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Ahh, I get it, thx! That clears things up!



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