Seed Container Idea & Question

[AlittleSalt]

Over the past 4 years, I bought tomato and pepper transplants. The were in the standard 2" transplant pots. I saved the trays and pots to use for starting pepper plants in.

First, the idea:

I got a full sheet cake bottom and lid from Walmart. They gave it to me. I cut one transplant tray in half longwise and put a full one beside it, and in those, 48 two inch pots. This fits really nice on the sheetcake bottom and the lid/dome stands 2.5" above the pots. = DIY pepper starting greenhouse.

Now, the question:

For the tomatoes, I am thinking of using 18oz. dark colored Hefty cups (100 pack) I've read using clear cups may not be advisable - so I'm not going to. Of course, put holes in/near the bottoms of the cups. I am going to fill the cups about .75 full and put plastic wrap over the top. Then after the seedlings emerge and grow up to the plastic wrap - I'll remove the wrap and add pro mix as the transplant gets larger. Question - What do you think about this idea? Please feel free to add ideas, comments, etc. I'm new to all this.

The soil I am using is 2 parts pro mix - one part MG seed starting potting mix.

[FLRedHeart]

I think it is a good method, except once my seeds break the soil or growing medium I get the plastic off ASAP, to avoid disease.

I suppose that might depend on how humid your place in TX is, and you can bet it is always humid here. But for $5 at Walmart you can also get a clear cover pluse 1020 tray for seedlings with plug inserts from Walmart which is what I used to use.

It depends if you prefer to transplant at that stage (a ~ 1" x 1" x 1.75" plug). I do. Starting directly in a 3" round is certainly a better plan and probably what the experts here wil recommend, but I use lights and simply don't have the room. I don't know how many seeds you are using, but I use only one or two per plug and select the best to plant before moving up to the pot (recycled yogurt container). I am sure every approach has it pluses and minuses.

Recently I did something similar to you ... got a cake cover (free from the nice lady in the Walmart bakery ... she mentioned if she gave me the bottom she would have to charge since that is what is counted for sales purposes) to use as a greenhouse for some seeds, Litchi Tomatoes, since they are a real beach to germinate quickly. Actually I tried them 4 ways, and nothing sped them up in my trial. It made no difference since after a month and a half they got some secret message all of them germinated magically together. Hope that helps for yours.

[AlittleSalt]

Welcome to Tomatoville FLRedHeart

My wife is letting me put up some temporary 1x12 shelves to keep all those tomato containers on. The area is between our kitchen and living room - so yeah, temporary.

Humidity won't be a problem after removing the plastic wrap. I plan on planting two-three seeds per cup and do like you wrote - remove the weaker looking ones.

Litchi is one of the tomatoes I am going to grow. I need 4 plants for a raised bed, so I'm going to plant 6 cups just in case. I'm glad you told us that they take a while to come up. Now, I'll expect it instead of wondering what's going on.

[FLRedHeart]

Thanks for the welcome, it's nice to be here. I've been following the posts here for a while so I knew knew you were going to plant Litchi tomatoes which was mainly why I posted. You are already late in getting them started! Figure on a minimum of 12 weeks for germination/seedling stage ... you are in April for them.

The humidity / disease problem is from the plastic covering here also, which is why I remove it ASAP. With good seeds, I don't even need it. If I lived in a drier climate I would still not keep my plants under it a moment longer than necessary to get shoots, not like you are saying to let them grow up to it ... I wouldn't do that part, also because the breezes inside the house IMO are helpful to the stem development.

The problem with the Litchi tomatoes is that they will take so long that things will dry out which is how I ended up doing the Walmart cake cover and you post sounded like that might be what you were finding too and sent you to Walmart.
I did funky things with the seeds after holding off on chewing out the supplier, but they still responded to nothing and took their own sweet time. I was amazed that the germination % was nearly 100 in a short span when they finally did emerge.

Also, they seemed to be much more sensitive to waterlogging than my other true domesticated tomato types. The growth and leaves don't look much like tomatoes, something like a pretty thistle, but they do get moving nicely once they get going, thankfully.

Good luck with them!

[Cole_Robbie]

It's not that your idea won't work, but I think you'll grow your best roots by starting in small cells and moving up to the cups after a transplant or two. I use cups, too, sometimes for seed-starting multiple seeds, but all the plants get transplanted multiple times first, from seed-starting mix into 48-cell flats, and then the cups a couple of weeks later. After the cups, the remaining plants go into 1-gallon containers.

Roots grow until they hit something, the boundary of the container, then they fill in the rest of the space. In a large container, they have a hard time making it all the way back to fill everything in. That's the logic. Tomatoes seem to like being transplanted. I have never noticed any transplant shock.

Once again, you may do fine with just the cups. I don't know for sure there will be a noticeable difference. I also like transplanting because it lets me take anything leggy and bury it a little deeper in the medium. You said you were going to add more medium to the cup so maybe you can solve that problem that way.

[luigiwu]

A little salt, do yourself a favor and go look at Craig's video series on DENSE sowing. Its amazing! Life changing, really!

[AlittleSalt]

I'm watching (Now listening) to Craig's videos. It seems everything I learned about transplant shock just flew out the window. My ideas came from trying to lessen the chances of transplant shock. Organic forums and sites make transplant shock out to be the ultimate sin - and you can't be too careful...etc.

Cole, I will seriously rethink using starter cells.

If I use starter cells or not, when repotting, I will only fill whatever size container I end up using about half full. As the plant grows - I will add more pro mix.

While dense sowing will be important to me one day, because I will be using this method to grow my favorites - I'm not ready yet. I am at my tomato growing infancy. I honestly cannot tell you if I like sweet, acidic, or highly balanced types because I haven't tried them yet. I've never eaten a GWR, YWR, OWR, BWR, Striped, Bi-Color, Heart, and most all other non red tomatoes. It was just a few months ago that I finally saw the difference between red and pink tomatoes. For years, and many posts here, I believed my favorite tomato (Porter) was a red tomato. It's not, it is a pink variety, and now, Thanks to you guys, I can see the difference. I'm glad I sent in 10 packs of pink tomato seeds for that category to the MMMM. It was mailed last Friday, and yes, I am excited to see it in the mail.

[greenthumbomaha]

Salt, go for the dense planting and potting up. There's just something about adding to the cup (besides you're missing on the fun of transplanting) that the soil on the bottom compacts unevenly with the top. Anything will work if time is an issue but you'll get much better results with the potting up steps described above. We live all year for this part of the grow cycle

- Lisa

[Worth1]

I go from seed starting cells to 1/2 pint glass mason jars that I drilled 1/2 inch holes in for drainage with a 1/2 diamond hole saw and a drill press.
The clear jar has zero effect on anything and you can see the roots grow.
Plus they last forever.
I'm eccentric and I do things way outside the normal.
Worth

[JLJ_]

FWIW, regarding cups . . . I use clear plastic 16 oz cups to start nearly everything.

Advantages to the clear cups are that you can see how the roots are progressing and that in the early portion of the growth period, when I have just a small amount of growth medium in the bottom section of the cup, the clear cup walls allow the seedling to get much more light than a solid cup would permit.

Advantage to starting with a small amount in the bottom cup section: as seedling grows, more medium is added, allowing the seedling to fill a smaller area with roots, then be 'planted deeper' by the addition of more medium, without having to actually change it from one container to another.

I don't top cups with plastic, but do top them with tulle squares held in place with a rubber band. Helps maintain moisture while allowing ventilation and, because I plant in sterilized medium, ensures that any bugs that show up as temps begin to warm are unable to get to the baby seedlings until they've had a chance to grow some. I remove the tulle when the seedlings reach the top of the cup. Some years seedling-threatening-bugs are not a problem, some years they are.

Works for me. YMMV

[luigiwu]

The benefits to dense sowing (for me) is beyond getting massive quantities of plant babies... It allows you to start very small using the best stuff possible (as you only need small quanities) - ie, a single heat mat, a single bag of the (more expensive) seed starter mix and then when I pot up, I can use whatever MG/cheaper potting mix. I still have a half a bag of seed starter mix left from last year (grew over 100 baby plants) but I will get a new bag this year to start fresh. I had an old seed cell tray that I cut up but you can also use small dixie/water cups for the seedling mix.
As you pot up, you'll be able to assess the health of the plants - imo, its just a really smart way of doing thing... Instead of having say tons of cups laying around with some that did not germinate. Last year was my first year seriously test-tasting tomatoes. I didn't know how successful I would be growing from seed. I really only needed 14 plants and gave away over 70 and made a lot of others happy in the process.

I liked the red beer cups I used last year but they are prone to tipping over when the plants got tall (I moved trays to the sink to water.) If they were clear, I would like it even better! I'll buy clear ones this year I think.

When I am germinating my seedings, I just used an inverted storage bin over my heat mat setup. Don't need any of this after they pop-up. They are removed from the heat mat/bin and taken under shoplights.

[AlittleSalt]

You all have given me a lot to think about. There are a few varieties of tomatoes (Like Litchi) that need to be planted last week that I'll be getting in my MMMM pack hopefully today or tomorrow. I have not found any seeds or seed starting anything in our local stores yet. A worker at TSC said they will be getting shipments of seeds later this week. Walmart gets whatever is sent to them whenever - so who knows.

I do have something sort of like seed starting cells. For lack of knowing exactly what they are called... We called them Dixie Cups in the 70s. Little 2-3oz. cups kids used for rinsing when brushing their teeth. I guess I could use those?

I have thought about the shape of plastic cups. A narrow bottom and wide at the top does mean it can be top-heavy even without a plant growing in it. However, I have been saving the smaller Folgers coffee plastic containers. I'll have to see how many we have saved. They are the net weight 11.3oz. size. The bottom is the same size as the top.

Edit: It turns out that we have saved 17 of them and another 13 plastic flower pots a little larger in size. That's a start. There may be more? Living with short-term memory loss really bites sometimes.

[b54red]

I use egg carton bottoms with 4 or 5 holes punched in each egg cup for my starting cells and usually plant between 3 and 4 seed per cell. I use the cut-off lid for a watering tray with the holes taped up with a piece of duct tape. I then pot up into regular Styrofoam coffee cups with holes punched in them.

As someone who fights damping off problems most years I would not recommend starting the seed deep in a larger cup because of the lack of air flow around the newly sprouted seed. I think it could possibly lead to more damping off problems. I only use UltraSorb from Auto Zone for all my small seed starting now because I get better germination and almost no damping off. There is a long thread on this forum discussing using DE as a starting medium which you might want to read especially if you live in a humid climate like I do.

[FarmerShawn]

I am a big fan of soil blocks, and I find that a meager two inch block grows and supports a 12 - 16 inch tomato plant just fine, and transplanting into the garden is a snap. Lately I have been combining the dense planting germination method with soil blocks. I start the seeds with Craig's dense planting method, then when I pot up, I unceremoniously mash the little seedlings into the 3/4" cavity in my 2" blocks, where they thrive until plant out. I like the space saved, and I love not having to buy or search for plastic or any other kind of pots.