I thought we'd mentioned them earlier in this thread, but for the moment I can't find the messages so perhaps I imagined it.
I really like the idea of using them. It's just the practicality of making them in the numbers I'd want. This is one side of my propagation greenhouse at the moment:
There's not quite so much on the other side yet. Maybe only ten trays. But then there are another twenty trays in propagators too. Each of the trays is 20 cells, so that's somewhere in the region of 1200 cells, plus perhaps thirty larger ones for the broad beans. I actually emptied three trays today, transplanting radish and peas, but immediately refilled them with flowers that my wife wants for the beds in the garden. That's an awful lot of blocks to make and I'll need far more before the year is out
In the meantime I've tried to make my trays less prone to breaking by punching a 16mm-ish hole in the bottom of each cell. The compost doesn't fall out, but it means I can (just about) push the plant out of the cell from underneath without crushing the plastic, which makes them vaguely like
these, but cheaper and more suited to the size of my fingers. Punching the holes out is another very tedious job, mind
Perhaps I need to invent a soil block making machine
James