Starting Onions From Seed

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Alan in Vermont

New Member
Last year I planted Walla Walla onions using started plants from Gurney's. They did well and I want to do more this year to try at our farmers market. A bit pricey to go with plants so I want to start my own from seed. I have slightly less than zero idea of how to go about it. Our average date of last frost is mid-May. From my reading it seems I can set them out a bit earlier than that and be safe. Anyone here have experience with growing onions from seed? I'll be gratefull for any and all advice.
 

RonsGarden

Super Moderator
Staff member
Good question Alan!
I start them in trays using a moistened sterile soil-less mix!
My trays are small 6" x 4" and 3"s deep, but any size tray will do! Make sure there's drainage holes on the bottom, so excess water can drain away!
Fill trays so soil is level with the top rim of the trays. Lightly pack down and sow seeds. Try to space them a bit...say 1/4" apart. (a bit less will do too!)
Thinly cover with more soil!
Lightly pat down the soil.
Use a mist type spray bottle to wet down the soil and then cover the tray with some clear plastic.
I have growlights that I use, but a bright south or east facing window will do nicely.
Depending upon species (and there are hundreds) they will sprout usually withing a week! I won't get into the species that require cold treament since most of the cultivars we use as a food source tend to require warmth for germination!
Remove the plastic once you see the sprouts popping up through the soil. Keep the soil moist letting the soil surface dry a bit before rewatering.
If you time it right the seedlings should be into their 2-3 leaf stage and ready to be planted out in the garden (in your case ->fields)! You will need to harden them off first for a few days outdoors in a bright light situation...each day place them into a more sunny spot.
I think that covers everything.

I grow ornamental type onions for the flower gardens.
Their starting culture can be a lot more involved!
I use their foliage when I need green onions for salads and stuff.
 

Flower4Yeshua

Super Moderator & vegemm
Staff member
ron about covered it....I also allow some to go to seed to get my seeds for the next years crop.......I found sets are faster...but seeds are fun
 

Crabbergirl

Super Moderator
Staff member
Mine have been in the ground for about 6-8 weeks through bad freezes and they look great! Onions are a crop that can tolerate freezing if your frost line is not too deep.
 

Alan in Vermont

New Member
I received shipping confirmation that my onion seeds have been shipped. Should have them in a couple days. They will go directly into 72 cell seed trays. I would normally plant them in flats and transplant them into cell trays but with very limited use of my left hand the transplanting isn't going to happen this year. Where there is bare ground the garden is thawed 6-8" deep with hard frost below that. There is still snow on most of it yet so it will be a while, at least a month, before I can start working in the dirt.
 

Alan in Vermont

New Member
I just direct plant mine.
That's nice to know and would be far more helpful if you had a location listed so we could know where you are. I figure I need to get the tops growing well before they can go outside. If I'm getting it right the plants will grow until they are seeing 12+ hours of daylight, at which time they kick over to bulbing. Since we will be seeing that level of daylight by early May I don't see how there will be top enough to grow a big bulb considering it's hard to plant even cold hardy crops before mid-April. I'm going to try some direct seeded as well as starting my own plants. And I backing my seed efforts up with a batch of started plants, just in case. Next year I will have a better feel for what does and doesn't work here.
 

Alan in Vermont

New Member
Seeds went in the pots on 3/13. Two 72 cell flats with two seeds each. Yes Virginia, there really ARE 300 seeds in that package! The weak sisters will be getting trimmed out at some point. Should be able to set them out in about 6 weeks. I think I'll try some high domes over the plants with black poly over them to limit hours of light? Any opinions on how big the seedlings can get before the hours of light trigger a bulbing frenzy?
 

Alan in Vermont

New Member
8 days into it and the seedlings are doing fine. I covered two domes with black plastic to keep the light duration low on the onions but stll be able to keep light on the rest of the wee 'uns.
 

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Alan in Vermont

New Member
I got lazy about posting to this thread as the onions were developing into transplantable things. They kept going tall and spindly with frequent haircuts as they grew and kept falling over to grow along the surface of the soil.

I was getting desperate, these things just weren't growing in a manner that seemed "right". I finally went berserk, do or die you little bahstuds! They had been growing under two "sunlight" flourescent tubes. I added two more, trimmed them short and set the lights just about on top of them.

VOILA!!

They darkened up and (finally) started developing multiple leaves(fronds?).

I wasn't able to get my hotbed loaded up this year so it was late before the plants went in, using it as a coldframe. Physical limitations combined with nasty weather kept me from setting anything into the ground until mid-May. I got the onions in just in time for them to get blasted with two days of mid-90s temps which were followed by most of a month of wetter and cooler than normal weather.

As of this morning they are 12-18" high and growing nicely. I dug around a couple stems and they are just beginning to expand.

I now know to plant plenty of seed, germination seems to be around 50% and go heavy on the lights. I will also start a few weeks earlier and try to have a bed prepared for them this fall so I can set them out by mid-April.
 

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Alan in Vermont

New Member
Since I took the pics they have started bulbing. Sunday morning there was no sign of it but by Tuesday evening there was visible swelling and cracking of the soil around many of the stems. It has been dry for a couple weeks and brutally hot for most of a week now so I started watering them heavily to both help growth and soften the soil so they can grow easier.
 

Crabbergirl

Super Moderator
Staff member
I still have a couple bermudas in the garden I need to pull. They store better in the ground than in the house.
Alan,
Are you going to have a truck market or are all these for personal use? Just wondering. I give a lot away but I am stingy with my onions. I have been thinking of canning onion relish . Just wondering what you do with all of your onions.
 

Alan in Vermont

New Member
I sell through a local farmers market, in a normal year. This year I may no do that. This is being the year of bad things going on in the garden. For openers I'm only working about half my normal area. As the result of some surgery gone awry I have very limited use of my left hand and it took me just a couple days shy of forever to get the soil ready and crops planted.

Dealing with the smaller space I cut way back on sweet corn, I've only got two varieties planted, one yellow and one bi-color. Both will be coming off at about the same time, generally not a good thing. I also put in some popcorn because the granddaughter thought it would be "cool". The sweet corn will go both to the market and I will probably set up on the roadside for a few days as well.

Acorn squash is starting to flower. I have 25 hills of then, planted in four batches about 10 days apart. Hoping I can stretch the season out to 6-8 weeks as I have an order for 30-35 a week for as long as I can keep them coming.

I didn't get a lot of broccoli started and what I had bolted in this heat wave we're having. It started to show some small curds and in two days they got about golf ball size and turned bitter. Nibbled on one this morning, had to go get a McGreasy breakfsat to get the taste out of my mouth. :(

Cabbages seen to doing OK, tomatoes are setting fruit, I sprayed them with copper yesterday just in case the blight comes around again. Cantalope was a fizzle again this year. I keep hoping for a year like I had with them in '08, vine ripened melons, just one step short of heaven. Pumpkins are doing well although they will get a little nitrogen nudge as they are a little light colored in some spots. While I do sell as many as I can I'm doing pumpkins primarily for the grandkids and their friends. I'm hoping to figure out just who will be coming this year so I can personalize a pumpkin for each of them. If the Atlantic Giants and Prizewinners yield like the PWs did last year I can scribe names in them and send the kids looking for "their" pumpkin.

The onions will probably be ready too much before anything else for them to make it to market so I'm not sure just what will happen to them. Last year we made a lot of relish that used cukes, cabbage, onions and peppers. There is still a lot of that left so I'm not sure we'll make any this year. Incidentally, red cabbage makes for beautiful color in relish.

Peppers are doing fairly well, seeing a few blossoms now so they will be a while developing.

I'm hoping that with what I have coming along I can get into the market for 6 weeks or so, time will tell.
 

Alan in Vermont

New Member
Onions are well into bulbing now. I started seeing cracks in the soil around them about a week ago. I watered them heavily then as we hadn't had any rain for 10-12 days. Then on 7/8 and 7/9 we got overnight rain, about 1.5" total which gave everything a kick. I took this shot this morning of what is currently average bulb formation.

Everything I have read indicates that you leave the exposed top of the bulbs uncovered. Anybody have any idea why? There is never any explanation of why they need to be exposed. For whatever reason that just seems wrong to me, I fighting down the urge to grab a hoe and hill them up.
 

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Crabbergirl

Super Moderator
Staff member
Hi Alan,
Yes you are correct on leaving the bulb exposed. Some of mine are all but the bottom 1/4 out of the ground. I beleiev it is that they will rot if covered. Something about needing to be on the dry side. That looks really nice by the way.

I too have cut the size of my garden. Sad realization of the aging process :(
 


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