If you’re having problems growing onions, here are some points that will help you.
I grow over a 1,000 onions a year and use to grow as many as 3,000 a year when I grew for market. I’ve always considered them an easy crop — even when I first started raising them 35 years ago. I guess I just stumbled into getting it right from the very beginning.
I never gave the “whys” a lot of thought until this year when I heard several folks say they haven’t had good luck with growing onions. To be more specific: One friend who planted about 150 transplants said his never came up. Another person who plants sets never gets anything but small pearl sized onions.
These transplants are now spring onions size. The month is May.
WHEN you plant onions is critical.
The general rule of thumb is to plant onions 4 to 6 weeks BEFORE the last freeze date in the spring.
Here’s the reason:
Onions will form bulbs based on the hours of daylight. In order for them to get big, they need plenty of growing time BEFORE they start to bulb. If you plant your onions when the amount of daylight is already enough for them to bulb, you’ll get pearl onion size onions.
You must plant early enough to give them time to grow before the day length is reach that triggers bulbing.
Numerous varieties of onions.
Planting DEPTH – Only 1 inch
I couldn’t understand why my friend who planted about 150 transplants didn’t have any come up. That is — until I found out the he had planted them 3 inches deep. Way too deep for onions!
When the drought broke in September, we had about 12 inches of rain within a few days and it brought his onions more to the surface. They started growing —-and this fall my friend has many “spring” onions.
So whether you plant sets or transplants – make sure they’re not too deep. One inch is a good depth.
Using SETS? The small ones make the bigger onions.
If you plant from sets and want big onions, use the smallest sets. (About the size of a marble.) Larger sets will make only green onions.
Sort your sets and plant the larger ones separate from the smaller ones. Then you’ll know which ones won’t make large onions. Thus, you can use the green onions while you are waiting for the others.
One last thing:
An onion transplant is an onion plant between 8 to 10 weeks old which has not gone through the bulbing process.
Overall, transplanted onions grow bigger and store longer than those grown from sets. If you have enough onion savvy — grow your own transplants. If not, some garden centers sell them.
If you’ve had trouble with growing onions, one or more of these four points might well make all the difference in your crop.
My garden in May. Rows of onions are towards the back and to the right.
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Other Posts on Onions:
Growing Onions – Determining When You Should Plant
Onions – Those to Enjoy as First Fruits and Those to Store
Onions – Tip – What to Do with the Small Ones
Onions Plants – A Bonus Can be Green onions in Winter
Onions – Starting from Seed is Easy and Economical
Bunching Onions – A Perennial Scallion Patch
Onions – More Reasons to Plant
How to Have Garden Onions April thru January
Onions – More Reasons To Eat them Fresh
Growing Onions – Problem with Rot
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All content including pictures is copyrighted by TendingMyGarden.com. All rights are reserved.
OK, so sets are the little bulbs without a green stem and transplants are the green stem without a bulb?
I’m so glad to know about the depth.
I never thought about it in those terms, Beppy; but yes, the sets are little bulbs with no stem and transplants have a green stem with no bulb.
Sets are produced by sowing seed thickly, which results in stunted plants that produce very small bulbs. The bulbs (sets) are set out the following year to produce either spring onions or large onions.
To get transplants, one sows seed the same year the onions will be replanted. The seed germinates and is allowed to grow about 8 to 10 weeks. It is then dug up and can be planted again to be harvested as either spring onions or fully mature onions.
Depth does make a big difference. I think a lot of people make the mistake of planting too deeply and never know why they’re not getting onions.
Best,
Theresa
hecent sizeello can i say that i have been trying to grow. d onions for 3 years now my latest problem is support.im trying some kelsay.and they are flopping over.
thanks for any help…yours derek leeds,,,,,,
Derek, I can’t understand all of your comment.
If your problem is that your onions are flopping over — the tops of onions fall over when they have grown as much as they are going to grow.
Hope this helps.
Theresa
My onions develop very loose layers so that only the center is usable. Any suggestions?
Thanks
Hi Rosalie,
You didn’t supply very much information so I can’t really give much of an answer.
Do you plant sets or transplants? When do you plant? Where are you located? Are you planting the proper day length onions for your area? How long have you had this problem? Is your soil good? What percentage of your onions are like this?
Sometimes when onions get “loose” layers they are going to seed. But usually the center would be a hard core at that stage.
A few onions sometimes develop a loose outer layer and the inside is good. I use those for spring onions.
Theresa
Hi Theresa, Just checking in about my onions. Planted them right when you suggested in March. How big should the bulb be now (beginning May)? We gently probed around the base of our onions (from Dixondale) today but none of our transplants have anything more than a shallot-sized bulb right now. Tops look green and healthy though. We graded them by size, and checked each size, all were similar. Are we still on track?
You’re still on track. Mine are the same. The onion won’t start growing larger until a certain amount of daylight hours triggers bulbing. Right now you want to have the tops grow and for them to get as many leaves (the top) as possible before bulbing starts. The more leaves — the bigger the onion will be.
Keep me posted Sandra.
Thanks Theresa, the leaves are green and lovely. Thanks for the reassurance.
My pleasure Sandra!
I started onion seeds last year, trans planted them 3″ depth and 1′ apart. I now have hard stalks with seed pods. Is there anything I could do to salvage these onions?
Hi O’Hara,
How wonderful that you started your own seed, but how unfortunate that you didn’t realize you were planting too deep. Never plant onions more than one inch deep. Space two inches apart if you are going to thin as spring onions, and 4 to 6 inches apart for bigger onions. I plant mine about 3 or 4 inches apart and thin to eat spring onions in early spring and summer.
Rather than to repeat what I have already written, please go to Categories to your left on the screen and select onions (under Vegetables). When you do more than a dozen posts on onions will come up for you to select from. Read those whenever you can and you will find out more about how to plant.
Onions bolting to seed can be caused by many things. Again, it’s great you are starting your own seed, you just need to do a little reading to find out more about the proper way to plant.
Also, O’Hara — a suggestion: Continue starting from seed, but just so you won’t be disappointed and also so you can learn more — order a few transplants next spring and see how they perform next to yours from seed. You’ll learn a lot from the experiment and coupled with what I have written on onions — I think you’ll do fine.
Let me know.
Theresa
Hi,
I planted onion plants in mid April from Dixondale Farms. One inch deep. I used their Organic Weed and Feed when planting and again 2 weeks later. Then in another 2 weeks I used a Seaweed mix on them. The plants have grown but not big and strong like they should be at this time. They were mulched about 3 weeks after planting with leaves. They are kept evenly watered.
The leaves are green but weak and some falling over already and this is only June 15th. What is wrong with my onions. I have 4 different varieties suggested for my area. Help please before it is too late and my onions are all over and failed. I’m in Northeast Ohio.
Thank you.
Hi Loretta,
I hate to tell you, but if your onions are falling over already that means they are finished.
From what you are telling me, you just didn’t plant soon enough. I know that most information out there (at least for my area) tells people to plant in April or May but I strongly disagree. Onions have to have time to stay in the ground and develop a strong root system and lots of leaves before daylight hours trigger bulbing. Once that magic amount of hours is reached for your onions – whether short day, long day, or intermediate — the onions will start to bulb. If they don’t have enough leaves they will be small. Nothing you can do at that point.
Many of my readers came to me for help with onions. There are two common mistakes people make. Planting too deep. (You did great on that — one inch is fine.) The other thing is planting too late. Once they corrected these mistakes there onions were fabulous.
I know it’s disappointing to try so hard to do everything correctly and then find out you missed one point — but gardening is a continual learning experience. This is something you won’t forget next year. You’ll correct it then and I think you’ll be fine.
Best,
Theresa
P.S. I just read your comment again Loretta. You said they were kept evenly moist. This could be a problem as well. If you are set up to water you should let the soil dry out before you water. Too much water and “wet feet” is just as bad as too dry. Read my post on https://tendingmygarden.com/watering-guidelines-to-consider/
Hi,
Thank you for the reply. I checked my records and I see I planted the onions April 19th. Our frost date is May 11 or 12 so it was a little less than four weeks before frost. I’m wondering if maybe we shouldn’t mulch them with anything. Planting one inch deep and then mulching with 3″ of leaves might be the same as planting too deep. We’ve always mulched them but things don’t work like they used to, it seems.
We’ve planted onions for 35 years and the last 4 years have been a challenge. We planted in good soil that was given a good amount of mushroom compost and the organic (well, natural) weed and feed from Dixondale.
The leaves are still totally green but weak with only 5 or 6 leaves. Maybe I need a soil test.
Thanks again for the reply. I will not water till the ground is dry and I certainly will plant earlier.
Loretta, I mulch my onions enough to give them a bit of early protection, protect the soil, and keep the weeds from growing. I sprinkle light straw on them when they’re first planted and do again as they grow stronger and bigger. You are right — you don’t want them to be too deep, but several sprinklings of loose straw (or chopped leaves) will be fine.
As you may or may not realize if you are a new reader, I am an organic gardener.
Dixondale weed and feed is not organic. (The “natural” means nothing. That’s just a marketing ploy.)
You indicated that your soil was good and had a good amount of mushroom compost in it. I personally see no need to fertilize onions – especially with nice soil rich in organic matter. I’ve never fertilized them in the 35 years that I’ve been growing them and I’ve always had excellent crops.
You said you had planted onions 35 years and indicated that you’ve only had problems these last 4 years. What is it that you did differently? I would be most interested in hearing all about it.
Also, can you let me know how you found my site. I’d certainly appreciate it, Loretta.
Theresa
Hi Theresa,
Thanks for the second reply. I’m very sorry to hear that the weed and feed from Dixondale is not organic. I’m usually on top of that because we grow an organic garden too. When I look at my records I see we’ve been using Dixondales feed for the last five years! Up until that time we only used homemade compost or compost from a nearby organic farm and sometimes composted chicken manure. I bet that is the problem. Somehow the weed and feed is causing my onions to be stunted. Like I say, they are not turning yellow and falling over because they are ready to be harvested soon. They are just not thriving. Now I can’t even say they are organic and my soil is probably contaminated. I have about 200 onions in. I have a picture from a number of years ago of one of the harvests hanging to dry and the onions are big and beautiful. Not lately.
Nothing to be done about it now but I will certainly go back to our old way of planting. I thought I was doing my onions a favor but instead I might have caused the problem. It’s the only thing I can think of. Thank you for helping me solve the problem. We’ll see next year.
I found your site when I Googled…problems growing onions. Glad I found you. I will be looking over your site. Thanks again.
Loretta
PS…Do you grow your onions from plants or sets? For years we planted Ebeneezer onion sets and had the best of luck. They grew big and lasted well through the winter. Then I switched to the plants because of all the great varieties. Maybe next year I’ll try a batch of sets and a batch of plants and see which does better.
Loretta
Glad I could help bring the cause of this problem to light, Loretta.
Appreicate too your letting me know how you found my site. Hope you’ll look it over and find it to your liking. I’ll look forward to hearing from you again.
Theresa
I grow from plants, Loretta. Overall, plants give you better onions. That being said — Ebeneezer sets are good. I planted them when I first started gardening 35 years ago and always had success with them.
Keep in mind also that certain onions grow bigger than others. And you’re right — not many varieties are available as sets.
I know you will be successful next year and I will look forward to a great report. 🙂
Wishing you a great season!
Theresa
Loretta — I got to thinking. The weed and feed has corn gluten in it. The corn is more than likely GMO corn. There is no proof (yet) of course — but I wonder if that was the reason it effected your onions.
Just something to think about.
Theresa
Hi,
I bet you are right, the corn gluten could be the problem. This GMO in our food system is such a worry. The rest of the world seems to see the dangers of it, why doesn’t the USA.
Thank you and have a great growing year.
Loretta
Hello everyone. I came across some “sets” I believe as I was actually planting other veggies in a new garden. In searching for what to do with them i came across this site and learned onions are to be planted no more than 1 inch in the soil. I dug up as many as I could , about 30 and re-planting an inch deep as I found them 6 inches down in the soil. Is there anything I could or should do to help them along ? All advice is greatly appreciated. Btw, im in brooklyn, ny if that makes any difference.
Hi Dee,
By “new” garden I am assuming you meant that you have just prepared it and planted this year and that it was — at least to your knowledge — not used as a garden before.
If that is the case — you are probably finding wild onions. They could be down as deep as 6 inches in the soil.
Most people don’t enjoy wild onions and they are not worth cultivating.
I remember a time when my husband and I had no money and were hungry and ate wild onions because we had no other kind— but even then I did not purposefully cultivate them — just harvested from the wild.
There are so many wonderful onions to plant that I would recommend tossing the wild ones. If you have already planted and want to let them grow — they need no help.
Theresa
Hello Theresa, thanks for the reply. May I ask what you did not like about the wild onions? Is it possible they may have come from my neighbors yard? I ask because There is mint coming from his yard as well. I really do like onions and I prefer not to “waste ” them if they can be used even if as Pearl onions in soup. Also I bought a green onion plant but that will not bulb correct?i put them in a container with herbs.
I didn’t say I didn’t like wild onions, Dee. I said most people don’t enjoy them. When I had nothing else and ate them I liked them fine. My husband on the other hand did not like the taste at all.
There are so many wonderful onions to grow and enjoy and although wild onions may be novel for a gardener —there are lots of other that have a better taste.
Just make sure the ones you are finding really are onions. (They should smell just like onions.) I’ve read that there is a look alike that is poisonous. So make sure you know they are onions before eating them.
Wild onions spread by their seed. So it’s possible they worked there way from your neighbor’s yard.
When you said you bought a green onion plant I guess you mean you bought a scallion or green onion in the grocery store. At this point in time — it will not bulb.
Hello Theresa, I am a UK gardener but came across your webpage whilst looking for a solution to onions dividing. A friend of mine is growing Red Baron onions and they have divided up similar to shallots. I haven’t seen this before and I’ve been unable to find anything about it on the Internet – have you come across this before and if you have, do you have any ideas why this has happened?
Hi Lynn,
Welcome to TMG.
As you already know Red Baron onions grow one per seed. I couldn’t help but wonder two things:
#1 – Are they really Red Baron onions?
#2 – Maybe onion seed was planted and when they came up all together your friend may have though they were dividing.
Theses guesses are a stab in the dark because Red Baron onions are know to be one per seed onions.
Hope you solve the mystery and will let me know if you do.
Have a great gardening season!
Theresa
3 years ago my yellow, white and red onions did wonderful–I had onions through the winter and almost to summer the next year. Last year, not a one–they all rotted in the ground. These were planted in the same garden plot as before, just a different row area. So I tried again this year. This year (as some did last year), they have grown like they are siamese twins. If I strip off all the rot around the onion, eventually I find 2 onions joined together at the base, or growing out of the base and splitting. Usually there is very little good onion in these ‘twins’. I’ve not tried growing onions from seeds yet–only sets. What causes the onions to ‘mutate into siamese twins’? I plant them 6″-10″ apart, maybe more than an inch deep, not much more. I’m baffled.
Pam,
From the information you are giving me – I don’t have a clear picture of your situation.
Where do you live? When do you plant your onions? Are you planting onions to go through the winter in the ground? Do you consistently renew your organic matter in your bed? Is your soil well-drained?
When your onions did well 3 years ago — was that the first time you had planted onions?
I can tell you that onions grown from sets sometimes produce twin bulbs. It can be caused by planting at the wrong time or growing in poor soil.
Rotting can be caused by planting late in the year and the onion plant will rot and start a new one inside as you described.
Rotting can also be caused by water logged soil.
Theresa
Theresa,
I’ve only been growing onions for a couple of years with some success. I sure appreciate the information on your website. I mulched for the first time last year and most of the onions did well. My questions are in regards to the planting date. I am up here in northern South Dakota. Our last frost date is May 12. Our first 15 hour day is May 17. I have the mulch down already awaiting some snows this winter. So, if I understand you correctly, I should plant somewhere between April 1 and April 15? The mulch I put down is probably 6 inches deep on the average. Would I just place the onion set or plant about an inch down or should I make sure it gets to the bottom of the mulch where the soil is. Thank you.
You may have to do a bit of experimenting, Sparky, to fine tune exactly which date is best for your area.
Even though the rule of thumb is to plant onions 4 to 6 weeks before the last freeze date of your area — I usually plant even 8 weeks prior to that.
For example: our last freeze date is between April 1 -15. I have planted onions as early as the first of February, but I usually start planting those last two weeks in February. Then I plant more onions the first week in March.
I’ve been doing this a long time and have been very successful with it, but always in the back of mind — I know that if you plant way too early it can be one of causes of early bolting in onions. (hard neck)
The main thing you want to do is give the onions plenty of time to grow before the day length triggers bulbing.
You should be fine planting April 1st. But if you can — why not plant a few that last week in March and see if there is a difference in the two plantings.
I’m sure you understand that you can’t plant in frozen ground. But with your nice layer of mulch — your ground should be just right.
Pull enough of the straw back so that you can plant the onion into the soil. One inch depth. Then gently push the straw up to the base of your planted onions.
I approach it a bit differently. I pull the straw back from the entire bed. Plant the bed. Then sprinkle straw to cover the entire bed lightly. As the days go by and straw settles, I continue to sprinkle more straw on until finally there is a nice layer of mulch over the bed — without having buried the onion plants.
I hope this helps and that you will let me know how you do.
Theresa
You truly made a number of superb tips in ur blog post,
“Growing Onions | Organic Gardening Blog
with a common sense approach”. I may wind up coming back to your page eventually.
Many thanks ,Fawn
Is that straw around your plants? Is that for weed control or moisture or both. Im trying to grow Kelsae onions I realized I started too late. My concern is the soil in Iowa is so heavy and rich the onions don’t get very big. Any tips on digging a trench and adding a soil mixture. Thanks Jim
Ebeneezer onion sets never heard of them. Ive always done sweet spanish. Where do I get Ebeneezer sets? I do know vidalia do not do well in Iowa.
Jim — you can google where to get Ebeneezer sets.
Yes, that is straw around my plants. It is for both weed control and moisture and much more. My site is filled with information about mulch and why I use it.
My way of gardening is based on soil improvement — rather than adding soil mixtures, so I have no tips for you on that.
If you’re interested in how I grow onions you may want to read the more than a dozen post I have that give the specifics about how I grow them.
Theresa, my onion starts just arrived today. My garden is still a little frozen. I went out there and pulled back the leaves that have covered the new onion bed that I prepped last fall. Can I plant the starts in the cold soil or wait till the soil warms up? Our forcast doesn’t look too promising.
Thanks for any advice.
Danita
I am understanding that although your garden overall is still a little frozen — the soil in the bed for onions that was covered with leaves is workable.
If I am correct in this understanding, then it’s fine for you to plant your onions Danita. They don’t mind cold soil.
After you plant — mulch by sprinkling straw and/or leaves onto the bed again. As they continue to take hold and grow — you can continue to sprinkle more mulch on — so that by the time hot weather arrives the mulch will be sufficient to stop weeds and hold in moisture.
And don’t worry about freezing temperatures after you plant. They’ll be fine — especially since you’ll have mulch on the soil.
Let me know if you have more questions.
Theresa
Thanks Theresa. It was sunny today and above freezing so alot of the snow melted. The ground that I prepared is definitely workable so I will be out there tomorrow planting my onions.Thanks again for the information and encouragement. Hopefully my onions will look as good as yours do.
Danita
I feel sure they’ll do fine, Danita. They won’t look grand for awhile. Takes them a few weeks to get established. Even mine don’t look so great right now although I can tell they’ve rooted because they seem to be standing straighter.
Theresa,
After having no success, I gave up on onions years ago. This past winter I decided I was not going to let onions kick my butt any longer. All winter I googled and read advice here and there. The advice on your blog just made so much sense. I read everything that you wrote concerning soil prep and onions. Here it is in the middle of May and I have the best looking onions that I have ever had at any point in any season.
The leafs on many of my onions are so long (16″-24″) that they are breaking over in the wind. Is this a cause for concern? Could I or should I just go ahead and cut those leafs off or should I just leave them alone?
Thank you for your generous advice!
Jr.
What a GREAT success story Jr!! Thanks for taking the time to let me know.
Your onions sound great. Just leave them alone. No need to cut them off.
Keep me posted. Keep up the good work.
Sure nice to have you reading.
Theresa
P.S When you have a chance, Jr, let me know what state you are in. Thanks.
Central Illinois. (nOtChIcaGo!)
THANKS!
Theresa, I live in northern CA. It rarely freezes here. My local nursery advises planting in late fall which I did. Plants looked good throughout winter and spring. In late spring all the plants put out scapes and I cut them off, but when the plant’s leaves fell over in mid-May (too early?), I harvested them. After drying, I found that most of them had hard, unusable cores and wrinkled rings. All the worst plants had large scape stalks with hollow, dry interiors. Am I cutting the scapes too late or too high? Or am I doing something altogether wrong?
Hi Robert,
It’s disappointing to put all that effort into a crop and have it disappoint. Sorry you had to experience that.
By the way — garlic has scapes and onions have stalks.
I’m guessing that you planted onions sets. (Onion sets are small dry onion bulbs.)
Onions are biennial. They grow the first year and if allowed to stay in the ground (or if sets are planted) most will set flower and make seed the second year. To make that seed they send up a hard stalk — hollow in the middle.
I plant from transplants (small onions plants) and even then a small percentage will make a hard stalk. (These are called hard necks.)
When I see an onion doing that — I pull it and use it right away because as you have found they are no good if left in ground. And as you have also found — there is no need to go through the curing process because they are not suitable for keeping or eating.
Since you live in California where is rarely freezes I would suggest you start your onions from seed in the fall. Once they are about 4 inches tall — you could plant them in the ground. This way — you’d have a very minimum of hard necks — if any at all. You might want to read my post https://tendingmygarden.com/growing-onions-from-seed/
Also — to hedge your bets — while you are in the learning curve — you could order transplants (onion seedlings) from someplace like Dixondale Farms and plant those about December or January. (I’m not sure how late/early Dixondale makes transplants available.)
I feel confident this will solve your problem. There are many posts on onions on TMG. You may want to read them all in the meantime.
If you want to plant in September or October — plant sets and pull them as spring onions. I always have a few in ground during the winter for those tasty “spring onions”.
Theresa
Help, My onions have been planted to deep. Do I need to dig around them or pull them up? Could I flood the rows so they will wash up closer to the top.
Margie the only thing that I would feel comfortable in recommending is to gently pull the soil away from each onion. This is something I would do over a period of days. A little bit at a time.
Good Luck!
I usually have a good crop of onions each year from sets, planted in February.
They do tend to go through a stage when the leaves are a few inches tall of flopping and curling but have always set themselves right again after a couple of weeks.
Unfortunately this year they have not corrected themselves and seem to be soggy and disintegrating at the neck. Any ideas what I may be doing wrong as think this may be the first year I fail?
You did not give me a lot of detail Tanya.
But —onions sometimes can be subject to a fungus that makes the roots rot. In order to avoid this problem and any other — it is important that you rotate onions and only plant in that location every 3rd or 4th year.
And of course you want follow the principles of a healthy garden talked about on TMG.
My onions are starting to go to seed whith white tip tops. So much rain here this year in Iowa will this put the hurt on my crop? Is there anything I can do?
Jim — I way I understand is that you are asking if the over abundance of rain will hurt your onion crop.
Too much rain can hurt your crop but doesn’t necessarily have to hurt it. We’ve had a lot of rain this year but I have excellent drainage and mulch on the beds. In addition to the other things the mulch does — it keeps pathogens from splashing onto the onion leaves. And I have not had damage from the rain.
Hopefully you have good drainage and mulch down and that your onions will be fine. If you don’t have good drainage and mulch — make sure you do in future years.
Regarding the onions going to seed — eat those fresh relatively soon. With the hard seed stalks — they will not cure and will not store
Hope this helps Jim.
Theresa
The tops of my onions are out of the soil one half inch to one inch. Should I cover tops with more soil or mulch or just leave them alone?
Onions need to have some of the bulb exposed to light, so that’s not a problem, Don. They should be just fine if you leave them alone.
Theresa
Is it advisable to chop and dry onions, excluding the core, that have put out stalks? The rings are pretty rumply and separated from the core so I wouldn’t use them as slices or rings, but how about powder or as an ingredient in building up a vegetarian or chicken soup stock?
Robert, I’ve never dried onions and all I can tell you is that I see no problem with chopping and drying the ones that have put out stalks (excluding the core). I also liked your idea about using it as a powder or as an ingredient for soup stock.
Theresa
Hi! Thanks for all the info!
Ok. I planted onions the first time this year and planted them in clumps, like they came from the nursery.
Do I seperate them now and space them so I can get them bigger bulbs?
Can I trim the tips for green onions whenever I want?
I live in Winnipeg Canada so they’ve only been in since Father’s Day. They’ve got a teeny bulb. It’s July 6th now. Thanks.
Squirrely,
In cold climates, onions are planted in the spring. A good rule of thumb for planting onion transplants to the garden is 6 to 8 weeks before the average last frost date.
The clump of onions you get from the nursery are then separated and planted. Spacing can vary but a good start is about 4 to 6 inches apart.
In order to get big onions you need to plant in plenty of time for top growth to occur before the number of daylight hours triggers bulbing. That way, larger onions are produced.
I would suggest you study the various posts I’ve written on onions.
Rereading the post you left your comment on would be a good start.
Next — I suggest this one: :https://tendingmygarden.com/growing-onions-determining-when-you-should-plant/
Then scroll through these posts and pick more to learn from:
https://tendingmygarden.com/category/vegetables-2/onions-vegetables-2/
As far as trimming the tips for green onions — I would set aside a certain number for that purpose. The top green growth feeds the bulb – so you’ll want to leave some alone for bigger onions.
Good luck.
Theresa
I grew onions this year and planted them as soon as the sets arrived. The nursery says they ship them at the right time for planting in our area but maybe they were late due to the number of garden orders with Covid-19 this year. The tops have fallen over but the onions are no bigger than the sets were to start with. I am, of course, disappointed. Should I cure them and plant them again next year?
Karen,
If you cure and replant you have at least a 99% of getting only spring onions and/or onions that will bolt.
So I can better understand your situation, tell me where you’re located and the date you planted the onions. This information will allow me to be more helpful and perhaps know what went wrong.
Theresa
I will take that as a No. I’m in zone 5b and I think they were planted near the end of May.
Karen — your problem with the onions was planting too late.
Onions need plenty of time to grow as many leaves (top growth) as possible before daylight hours (coupled with warmer temps) trigger bulbing. The more leaves they grow the bigger the onion. (13 leaves is the maximum.) Once bulbing is triggered top growth stops and the onions bulb.
Using Lincoln Nebraska as an example since it’s in zone 5b ——by the first of May you’re probably getting almost 14 hours of daylight which is enough (coupled with warmer temps) to trigger bulbing in both long day and intermediate varieties. By the end of May you’d already be getting 15 hours of daylight.
A general rule of thumb is to get your sets or transplants in 6 to 8 weeks prior to the last frost. Let say your last frost date is April 27 — then it would be a good idea for you to plant the first part of March.
This post will explain things in more detail: https://tendingmygarden.com/onions-helping-a-reader-should-she-plant-according-to-directions-on-the-package/.
Theresa
PS – Karen, you’d learn even more if you cure and plant some of those small onions.
I’d even put a few in the ground after curing — maybe about September. You’ll have some nice spring onions to enjoy in the fall. Then I’d plant a few in March of 2021 and see what happens. If you get just small onions — they’re still delicious.
Hi Theresa 🙂 Have you ever planted onions in the fall?
Yes, plenty of times.
How they do here in Virginia depends on lots of stuff.
Planting sets (that developed from seed I planted last spring) will give me great spring onions
fall, winter and the coming spring.)
Planting a fairly good sized bulbing onion will give you a seed stalk.
Seedlings started from seed this fall will give various results based on weather conditions
AND how large the seedlings are.
Smaller seedlings can be prone to not making it if the weather conditions are not just right. I think with some protection they should do ok. If I have time I’d like to try that this fall.
Pencil sized seedlings should do better and withstand the cold temps better — but I’ve not had pencil sized seedling in the fall.
I can’t remember who they are – but there are growers that have had luck with planting the seedlings in the fall and having them produce good onions.
The info I read didn’t say — but my guess is that they lost some as well.
When I planted the small seedlings in my garden to winter over — I lost half.
Theresa