Soil Blocks

Anyone here have experience with soil blocks and soil blockers?  Please share what you think of them and any tips about them you have.

I do like the idea of direct seeding where possible but time and situations don't always allow for that.  I don't like the transplant shock associated with trays and pots and I'm not that impressed with peat pots or peat pellets (one they need to be purchased every year and are not all that great in their function anyway.)  I've tried the newspaper pots made by wrapping news print (or old phone book pages) around a suitably shaped/sized object but that was tedious and really quite similar in function to the peat pots, so I was wondering if soil blocks work any better.

I'm likely to do home made version of a blocker to see what I think before I decide if it is worth buying a "blocker".

Do they really hold together well enough for handling and transplanting?

I usually use recycled 4" pots, and have used soil blocks, and am getting back into them this spring.  They can work great but you have less room for sloppiness.

Eliot Coleman makes the best case in his New Organic Grower (this man is not sloppy).

You are dependent on peat mining--unless you substitute compost.  I haven't experimented enough to know if you can get away from peat, and still create a compressed block that is penetrable by roots.

I really like getting 50 starts from a flat that has room for only 20 4" pots

Once the dry out they are hell to wet.  A mister would be good.  I have also bottom watered with plastic flats in a basin made of plastic and scrap wood.  Too heavy a watering from overhead can erode young blocks.  Don't let them get too dry!

They are pretty easy to handle, even when new, and quickly stabilize with roots.

I have a 1.5" four-block press--I could very easily see wanting more blocks per pressing if you were scaling up beyond home production.

I also recycle plant pots but was thinking there had to be a better way.  The plant pots take up so much space and cause so much root circling but if you don't let them build up a certain amount of roots in the pots, the dirt tends to fall apart when transplanting etc.

I read an article on some site last evening about how you either need peat or you can use a mix of coco peat but coco peat won't do it on it's own since there are no long fibers to help hold it together.  However coco coir pith I guess has fibers and could be used completely instead of peat.  Of course with coco products you need to make sure that they are well rinsed of the salt water and preferably composted aged coco products are best.  Lots of details to sort out when creating a mix I guess.

Now I do have worm castings and from my experience in handling them, I bet a pretty good mix could be made with a mostly worm castings and only small additions of other things but that is only my guess after watching a few videos of the blockers in action and having handled worm castings quite a bit.

I was thinking of using capillary matting under the blocks to provide constant bottom moisture but not too much.

I wonder if button mushrooms or a similarly easy-to-grow fungus might be used to bind your castings or leaf mold together, pasteurizing once the mycelia are strong enough.

I could also imagine growing buckwheat micro-greens in block-shaped molds, on a schedule timed to supply blocks enough for the intended planting schedule. It would be something like re-cycling pots, but the plants intended for transplant would get the air-pruning action that the buckwheat plants before them had missed out on.

In both cases, the molds could be some multiple of the intended block size, and blocks could be cut after pasteurization/harvest.

TCLynx wrote:
I was thinking of using capillary matting under the blocks to provide constant bottom moisture but not too much.

That reminds me of a neighbor who made little custom trays with 1/2" soaker hose running between two rows of blocks.  Some water wastage, and kind of expensive in plastic, but it worked well on the same principle.... What is capillary matting?!

Capillary matting is essentially a textile that wicks enough moisture to supply bottom water to containers sitting on it.

It can be set on a bench and have an edge hanging down into a container of water and it will keep the plants watered.