Okay, I know everyone has their favorite way of doing things. For me I have many crosses 5 seeds+ and some long crosses with 200+ seeds this year.. so I wanted a way to economically germinate them in sterile media (not a baggie). The whole baggie thing does not work for me with so many seeds... i don't want to be under the gun and i dont want to disturb seedlings until they have real roots and 2 or 3 actual leaves. At that point my intention is to transplant into soil using deep 1020 inserts (36 per flat... 1 seed per cell)... AND then when the time is right put them in the ground. Sowing seeds direct into the 1020 36 cell flats requires expensive humidity domes or goofing around with saran wrap... not for me... high costs and high labor will lead me to drink.. more than I should. Plus I really only want to plant them into cells once they germinate.... i dont need wasted space in flats where seeds do not germinate... and plugging those holes with new seedlings introduces labeling issues... who needs seedling Vampire Lady x Heavenly New Frontiers in the middle of Pirahana Appocolypse x Edvinas Misiukevicius? haha I mean we all do... but it would be better if they had separate growing areas.

I have searched and searched and searched, and found three options that seemed viable (1) the roasted chicken plastic containers (like costco chickens are sold in.... nice domes.. a little expensive and a little large... have more space for leaves than roots... not a bad option at all). (2) Berry containers like in the grocery story (have vents on top and bottom so need drainage and venting is very easy.. they are not very tall), (3) living lettuce containers (7x7... nice size... equal root and leaf space... cheap... 100% recycled PETE).

I have opted for the living lettuce containers.... they are the perfect size to germinate 36 seeds (a flat's worth). They are 7" x 7" x 5 1/4" tall dividers can be used in the shape of a cross allowing for 4 crosses in one box.... and each side can be labeled with a marker as needed. The lids can be loosely placed on top, or securely... or they can be opened. I figure... worth a shot. The prices vary a great deal... you can get them for pennies if you want a zillion of them an order off of alibaba in China.... but in the USA a case of 420 seems to range from $73.50 to $150... I just placed an order.

I opted to pay the $73.50 plus $24 shipping... the case is 40lbs....

Let the experiment begin.

If anyone else has similar needs.. this is where i ordered:

https://producepackaging.com/s...

I think it's a brilliant solution! Where will you keep them? Do you have plenty of room?

I have a dedicated room I just put together on the lower level of my home (a walk out basement) that has an inside and outside door facing the creek... so I don't need to track dirt thru the house. There is already mud all over the floor and I am just setting up the room! In the room I have nine 48" x 18" wire shelf units each with 5 levels (4 wire shelves and the floor). 8ft LED lights are ziptied to the underside of the shelves and mounted on the ceiling. Mylar reflective film all over the place (very cheap on amazon). Each shelf holds 4 standard 1020 flats. So that's 180 flats... each with 36 cells using the deep inserts. So, I should be able to accommodate 6,480 seedlings planting 1 per cell.

In a different room, I have a larger 24" x 10 ft Shelf unit (5 tiers) that could potentially hold nearly 300 of the lettuce crispers... at 36 seeds each that's about 10,000 seeds (not that i intend to plant all at once). Going to stagger the planting over several weeks.

Moving forward I would like to limit my activities to the 1 room... but this is my 1st serious year and I had problems with impulse control and seed acquisition!

If you are looking for a good deal on metal wire rack shelving units... the best deal i found was on homedepot... they have a 48x18" 6 shelf unit for $82.. It is extra sturdy and has wheels. Order online and ship to your local HD. If you use the floor, you only need 4 shelves... that leaves 2 to spare... so buy 2 units... then you have 4 to spare... then buy 4 extra poles... pole prices are all over the place... cheapest i found is from Menards (if you have that chain) Two 72" poles for $14. They are 3 times that at homedepot... so if you dont have a menards... hunt around the local shops you do have. So.. you can get 3 full units for under $200 plus tax. That's enough space for over 2,000 seedlings planted 36 per 1020 tray.

Regarding LED lights... i opted for 8ft 120 watt LED tubes (simple and they plug right into the wall). The light produced is 6000K which is reasonable for vegetative growth. All 8ft units are not the same... these have 4 rows of LEDs angled at 120 degrees for max dispersal of light. Many are flat with only 1 row. Got mine off ebay... $17 each in quantities of 20... up to $24 each if you only buy 8. I am using 2 per shelf level... so two 48" shelf units end to end with 4 shelves each plus ceiling means ten 8 ft lights. They sell 4 ft lights as well... if you cant put your shelves end to end or need an extra 4 ft in the case of 3 shelf units. Spend some time on ebay finding the best option/price.. look at the number of LEDS per foot, angle of LEDs etc. Also... if you want to do flowering... of anything... add some small red LED units. You can buy "pink" led grow lights but they are way more expensive and are nothing more than white with a few red LEDs mixed in.

Some people are fans of blue LEDS for veg growth... or mixes of RED and BLUE with little white... to each their own... i know its the thing for cannabis growers but i used mixed RED and BLUE on african violets and they did very poorly... plus it makes the room dark and creepy from a human perspective... so I like cool white (which has a bit of blue) and add in a little red if called for.

Sorry to go on and on

No, you can go on and on. It's useful information!

Wonderful set-up, Jeff! I hope you will post the progress of your project and share your experience along the way. Looking forward to see blooms from your seedlings a few years from now.

"i don't want to be under the gun and i dont want to disturb seedlings until they have real roots and 2 or 3 actual leaves. At that point my intention is to transplant into soil using deep 1020 inserts (36 per flat... 1 seed per cell)... AND then when the time is right put them in the ground."

From my experience growing seedlings, I found that seedlings did best if they were planted together rather than individually per cell. I would go with a bigger cell and put 4-5 seedlings in each. I don't know why this is the case, but perhaps the competition between the seedlings cause them to grow better? Anybody out there knows why this maybe the case? I guess that's why daylilies are commonly sold as double fans. They grow better and increase faster if you start with a double fan or more than a single fan.

Second, you should have a ready supply of Gnatrol or whatever you will be using to rid of fungus gnats. These gnats will go after your young seedlings esp. those with 2-3 actual leaves ruthlessly. Once the seedlings become more mature and can fend for themselves, the gnats is not much of an issue. Good luck!

I think your system is brilliant also!
And, I agree with what Karen is saying about the gnats, but I believe that you are on that already.
I am wondering how you are going to plant all of those seedlings??? Maybe with a tractor? I know I can't do it here in VT... unless I replace all the soil. I mean rocks...
This is a really exciting project and I hope you post more about your progress. I know from the LA that you have been buying some really excellent crosses! I can't wait to see your seedlings!!

I have been thinking that this year I will plant each cross (5 to 8 seeds) in a larger pot and just leave them there until planting outdoors. I spent a tremendous amount of time last year transplanting, first from the sprouting seeds in the baggie to an 18-cell flat (one cross per cell), and then later splitting out to individual solo cups, and finally to the seedling bed. I'd rather skip a couple of those steps, and am thinking about how to do it.
All the best.

@kousa

From my experience growing seedlings, I found that seedlings did best if they were planted together rather than individually per cell. I would go with a bigger cell and put 4-5 seedlings in each. I don't know why this is the case, but perhaps the competition between the seedlings cause them to grow better? Anybody out there knows why this maybe the case?

It depends on how you determined that the seedlings did best if they were planted together. It would be unusual for them to do so, as when they are together they will compete with each other for light, water and fertilizer. That typically results in plants doing less well than when they do not have competition, for example since they are sharing those resources and therefore not likely to be getting optimal amounts. However, when they compete for light that makes them "stretch" as they grow, as they are being shaded by the neighbouring seedlings. Then they can appear to be growing "better" because they are taller, but they are not growing as well as they could be if they did not have neighbours. On the other hand, more seedlings in a container may reduce the effects of being overwatered (as one example) and therefore they may seem to grow better because they are less likely to be stressed. As another possibility more seedlings in a container may reduce the effects of being over-fertilized. In both these cases the over-supply would have to be minimal since the presence of the other seedlings would probably not reduce the oversupply by very much.

@admmad "better" above means that the seedlings planted together were stronger and healthier and less death. Thanks for explaining possible reasons why the above occurred for me. I think you are correct! Perhaps I did overwater my single cells. Watering was varied with the single cells receiving more water due to them drying out quicker. My seedlings were not fertilized and they all received the same amount of light and type of planting medium. I just thought that they grew well together because they felt the need to compete for resources due to the existence of other seedlings in the same cell. You know, like how humans are sometimes.