Soil block newby

I stumbled upon soil blocks recently. As a concept it's perfect.  In reality I'm not sure.  I haven't read everything on permies, but a lot, and just scratched the surface on the internet in general. I have spent quite a few hours reading and watching info on soil blocks.
I decided to give it a try.  I bought a 3/4" soil block maker thinking I can start lots of seeds on the heat mat, with the benefit of up planting as soon as the seedling emerge from the soil, instead of having some fast germinating seeds get leggy waiting for the slower ones.  Also it makes 20 blocks at a time.  I did experiment with my soil mixture using shredded cardboard instead of peat or coco coir, and it worked well.  I made my own larger soil block maker.  I was going for 2"X2", but it ended up 3"X3". It worked, but needs modifications to make it easier to use.  I found some coco coir and peat moss ( not buying it anymore, but might as well use it), so I went ahead and used it. I also added some bone meal, and organic fertilizer to the mix since I figure it will be in it for a while.  
1st blocks held together very well, some roots stick through the bottom, so must not be to dense.  It was easy to replant as needed leaving the others.  The down side was it was only good for small seeds, medium and large seeds don't work. Some seeds sprouted on top so I can see root and seedling.  I wish I would have brought the 2" block maker.  
2nd up potting was super easy, just pop it into place.  I made the block so it made a 3/4" depression. I sprinkled mycorrhiza in the hole, and popped the seedling in. Sprinkled a little vermiculite to fill any gaps. Very quick and easy.  What I don't like is my blocks are to big and have only one seedling it takes up to much room.  I only made 12 of my larger blocks. The rest of the seedlings I used a good organic potting soil in plastic pots I had.  Each pot got 3 or 4 seedlings.  I decided if I change the tray under the lg. Blocks I might be able to get more in, because I still have seedlings that need to be up potted. When I tried to move them they started to fall apart, so I must not have gotten the mix right. I'm still going to do it because I need the space. I will just be careful, and squeeze it back together.
I started 17 kinds of seeds. I made 12 blocks. I made sure each block had a different kind of seedling in it so I could compare the difference.
I expected the single seedling lg. Soil blocks to out preform the plastic pots. At this early stage that is not the case. They all look healthy, but some in the pots have there first true leaves, and the soil block ones don't.  
It's early yet, and it's always tough to learn a new skill, but so far I'm not sure soil blocks are worth the effort.  The main benefit of soil blocks is not getting root bound, no transplant shock, and no plastic. Seems like if I start the seeds at the right time, so I can plant them outside before they become root bound then it isn't a problem.  I would still like to eliminate plastic, but I have lots of plastic pots and cups that still have years of use in them.  Well time will tell.
I'm interested in hearing what you all think. From what I've read it seems people love soil blocks, or hate them. Thanks

Last Spring I tried potting soil blocks in what looked like an ice cube tray with silicone bottoms to make them pop-out-able, and I didn't try very hard, so I didn't have great success with my transplants, but done right I'll bet they would've worked.

Your bottom picture has got me thinking "Mmmm I need to make brownies tonight!"

I transferred the lg. Blocks to a 10/20? Tray. I can fit 3 across so I can get a lot more blocks on the shelf. They didn't fall apart, and were easy to transfer. I liked using the sprout trays because there's a bottom tray I could put water in, and a preferred tray on top, so I could keep the blocks damp but not to wet. I will just have to be more careful with one tray.
I had 20 3/4" blocks I didn't use. I was able to run water over the top of them, and then soak them for about 10 minutes. I also reused some that didn't germinate.
I think I like starting peppers and tomatoes in the small blocks. They germinate so much faster than in a tray.  At least I don't feel as though I waisted my money.

I'm glad I posted this with pictures. I thinking the seedlings in the soil blocks haven't really grown. I actually watched a video on soil block mistakes this morning. But looking at the picture I see in under a week they have grown and are doing ok.  The soil blocks I put in the plastic pots do seem to be healthier.  I don't know if it's because of a looser soil? I watered the soil blocks well because that was one of the mistakes, not keeping the blocks wet enough. I also added an organic liquid fertilizer to the water. The blocks are made with compost, but maybe they need a little bit more. When I felt blocks they always seems to feel damp, but maybe it's not getting into the core of the block.  I'm also wondering about air flow. I surround the rack with aluminum foil to reflect the light. I meant to do the whole rack, but hadn't gotten to it. Now I'm wondering if the air is more important than the extra light.  
All in all everything is growing and looking healthy.

I watered a ton let them sit for a day, and tonight I removed all excess water.
I did some comparison pictures, and the seeds repotted in the pots are doing so much better.  It's not the air flow like I was thinking because some of the pots are on that shelf with the soil blocks and they are doing great.  We will see if the extra water and fertilizer does anything.
All the seedlings in the pictures were from the same seed packets ( like kinds of seeds). All were started at the same time in the 3/4" soil blocks, same watering, and time on the heat mat.  The only difference is when I potted up one of most of the seedlings was put in the larger soil block, and some into a plastic pot with organic soil. All had a little mycorrhiza sprinkled into the hole. I didn't have enough room to give all seedlings there own pot.  I put the soil blocks on a little container so the soil level was about the same height.

Hi Jen,
It is nice to read about your experiment. I think you are right about people either loving or hating soil blocks. I happen to be in the camp of people who love them. I bought a 2" block maker from Johnny's a few years back. I would generally buy all the ingredients and then make my own block mix modified slightly from a recipe that Johnny's provides that they got from Eliot Coleman. https://www.johnnyseeds.com/growers-library/methods-tools-supplies/seed-starting-transplanting/soil-block-makers-eliot-coleman.html

It does use peat moss, which I know is a controversial ingredient, but that is for a different thread to argue over :)

I have had great results, and rarely felt the need to add any fertilizer before transplanting. I never did a side by side comparison with pots, but generally with a little warmth, my tomatoes were easily 6" tall with good green leaves by 6 weeks in the soil blocks. My guess is that the pot has looser soil, which allows for faster growth... one of the trade offs of soil blocks. I've started several different kinds of flowers, several kinds of herbs, and several kinds of vegetables (primarily tomatoes and peppers). They all grew well except onion seeds. But I can't grow those in pots either, so I don't know if it was me or the soil blocks.

It is definitely important to keep the watering consistent, and it is harder to do without plastic surrounding the soil. I generally water from above only until germination or if it is a particularly hot day in the green house. Otherwise, I put water in the bottom of whatever container they are in and let the water soak up through. I have plans for a wicking mat with soil blocks sitting on top, but I have not been been able to test it yet.

Matt thanks for the input.  I want to like soil blocks. Any time I can eliminate plastic Im in.  I think it requires practice and patience.  It has to be wrong soil mixture, or water  to much/ not enough.  Everything else is the same. My hope is since I don't have to pot up again, which I will soon with the plastic pots, and supposed to have no transplant shock that the block plants will catch up.  Time will tell.

I think the size block matters as well. I only have experience with the 2" blocks, because in all my research, people said the 3/4" and the 4" blocks were difficult to deal with. A cool idea to "pot up" to the next size block, but in reality, not easy.

I seem to be using the papa bear from berenstain bears approach to using soil blocks. I have never experienced damping off until now. I never had gnat problems in the house until now.
It's a good thing I planted a bunch of seedlings in pots. They are doing great.  
It's not all bad. The 3/4" soil blocks started tomato and pepper seeds faster than any other way I have tried.  I also liked I could take the seedlings off the heat mat and pot up individually leaving the seeds that need more heat mat time in place.
Potting up was where it started to go wrong.  If I try this again, and I probably will. I will buy or make a smaller block maker.  I will probably stick closer to my experimental recipe using cardboard instead of coco coir and peat.  Stick with what works right?  Maybe a wicking pad?  
I have learned a lot. Not all good, but that's the way it goes sometimes.  

When I see mushrooms pop up in the garden, I don't mind because it is a hugel beet, so it's a fungal based system.  Seeing mushrooms popping up on my soil blocks is puzzling.  The mix is organic bagged compost, coco coir, peat, and some organic fertilizer, and some of the baby blocks mix. It was pulverized cardboard, organic bagged compost, and organic seed soil.  
Is this a good thing, bad thing?  Is it ok to leave, or should I repot it?

Hi Jen -
I am wondering if your soil mix is a little too dense. That could be a reason for the slow growth you are experiencing, as roots do need some air in the soil to grow through. And the mushrooms are disconcerting. Mushrooms and fungus gnats would tell me also that the soil mix is not sterile in addition to not draining well enough. Johnny's suggests using perlite in their soil block mix. Perhaps that would help lighten up the soil.
I have used the 2" soil blocks for a few years now. I think they work best for shallow-rooted plants, like grasses, leeks and onions. These I don't uppot, but transplant directly into the garden. I once tried my soil blocks for root vegetables, but I would caution against that - my carrots ended up being 2 inches long and flat bottomed although when I transplanted them they looked fine. Lol. Using the little soil blocks for starts make a lot of sense to me.
Since you are growing tomatoes, I thought you might be interested in this little tidbit - I know a number of people who have experimented with uppotting tomato starts directly into 1 gallon pots. This may sound crazy as a lot of plants would balk at that, but the tomatoes that were uppotted into gallons grew much faster than the ones that were put into 4" pots first.
Good luck!
Jen

Yay I was thinking it's something like that. There is perlite in the organic soil I mixed in, but I think not enough.  I hate to give up. The soil block seedlings look so crummy compared to the ones I pots, I'm thinking about tossing them in the compost. I guess I could plant them in my hugelkulture. Put the block apart a little, and cover it with something. Might be a better option than the compost, at least it has a chance.  

I wouldn't be too worried about the mushrooms personally. I don't use sterile seed starting mix, so I don't care that it is not. Unless the mushrooms are getting big enough to block or steal nutrients, I think it's a good sign of fungal spores in the soil.

Having said that... the problems you are describing sound like the mix wasn't quite what the seedlings wanted. I have only ever used perlite or peat moss, so I can't speak to other mixes.

For annuals, you may be overcomplicating it a bit. I use Pro-Mix w/myco and don't mix anything else with it for (when using for annuals) soil blocks. If the plants are in the blocks for longer than most before transplanting, like with peppers, I'll use some fish fertilizer a couple times just to make sure there is no shortage of nutrients limiting their growth, but that's it. The reason I don't mix anything else with the pro mix is because the density/compaction factor. You need the blocks to be compressed well for them to hold together, but if there isn't plenty of perlite or similar in the mix, the roots and air can't penetrate (or can't penetrate easily), and it stunts the growth of the baby plants. The 3/4" blocks have limited utility in my opinion. they dry out extremely fast, can only handle small seeds, and can quickly stunt the growth of the plant if not potted up right after germination. They seem to only make sense to use with seeds that have a poor germination rate, so you aren't investing as much soil mix and space into a lot of seeds that never come up.

I also start perennials, trees, shrubs, etc. in soil blocks, and for those I do mix in some vermicompost, alfalfa meal, and other slow release organic amendments to the mix, because the plants will be in the blocks much longer before going into the ground. Those are also the only plants I have found with the huge 4" blocks.

On a side note, I read in a couple different sources that 4" is the ideal size for most plants for root pruning, which is part of the huge sell for soil blocks. The claim was that any smaller, and the roots prune before they have reached a good efficient size, and the block quickly becomes filled with tiny,  but not as useful rootlets.  for me, this is important for the perennials, as the establishment or not of a strong root system before transplant can take years off of the time it takes for the plant to start producing, but for most annuals, I think the biggest advantage of soil blocks is space efficiency and eliminating the repeated purchase and use of a lot of plastic that ends up in landfills.

**I forgot to add that all the fungi/mushroom growth means is that there is some unprocessed plant material in your mix, which isn't a bad thing. The warm, moist conditions being provided makes it ideal for the fungi growth. I wouldn't worry about that itself, just the bugs and mold that could present a problem, but both can be mitigated with enough air flow.

Thank you all, I appreciate all the feedback.  

I have decided to keep the tomatoes and peppers. I will repot them and see if they start to do better. All the others are a variety of basil and parsley, and I have a lot of those that are healthy and growing well.  So they will go into the compost, and not waist space.

I'm glad to hear the mushrooms are not a problem. Any where else and I usually see them as a good sign. I just wasn't sure in this situation. I don't know what kind of mushroom they are, but have seen them in the garden. They didn't get very big, and have a very short life span.

I sprinkled cinnamon on top of the soil. I think I read it's supposed to eliminate the mold. It was just a little green on the soil.

I thought you had to add something to the soil to keep it together. When you say a pro mix, I'm guessing it's a mix made for soil blocks.???

I'm about to start round 2.  Normally it would be to late to bother starting seeds inside, but we are having a strange year. Our average last frost date is the end of January.  This year we have had two light frosts this week.  So I'm going to start more.  

Thanks everyone

Needing space I potted up, or composted my soil block seedlings.  I can now confirm the soil was to compacted. Little or no roots in the larger soil block.  So it's confirmed operator error.
Probably one of the things that keeps the masses from soil blocking is getting the right soil mixture.  I think it's just something you have to play with, and once you get the feel for it your good.  The funny thing is the mix I totally made up for my 3/4" blocks worked well, and the one I tried to use the "recipe" was a total fail! (I only loosely used the recipe, so it's my fault, not a bad recipe)
Oh well there's always next time.

I may have miss spoke about the damping off. A few of my soil block seedlings lost there leaves after I soaked the blocks in water with an organic liquid fertilizer.  The mistakes I made were maybe soaking to long, I was hoping to soften up the blocks. I shouldn't have used the fertilizer. I recently read not to use it until there are several sets of true leaves.
BUT besides making these mistakes that can cause damping off nothing happened besides loosing the leaves. The stem didn't die or look bad, no mold or rot, and nun of the other seedlings suffered ill effect. So I'm thinking maybe those very small seedlings couldn't handle the conditions I put them in?  I'm not sure, but it sounds like I would have lost a lot more than two of my seedlings.  ???

Hi Jen,
I can't speak to the fertilizer, but I do know that watering the soil blocks can be tricky. Too much and they waterlog and drown the plants, and too little and they get crusty and hard to soak up water anymore. I will generally fill the bottom of a tray about half way up the blocks and let it sit for a while. If all the water is gone, and the blocks look wet all the way up, good. If there is still water in the bottom, I try to get out the extra water.