I’ve got a couple from Johnny’s Selected Seeds. They’re well-constructed, sturdy, and easy to use. The 2” are very versatile for all but the largest seeds. Not crazy about the 3/4” ones. Seemed like a nice idea for saving space on a heat mat for germination, but they were so fiddly to construct and melted away with any sort of watering.
I thought the bottom-most video on that page was more helpful, it's this one:
https://youtu.be/bpNr5T4IJ-g He uses stuff from around the house and waters them with a cloth diaper dipped in water. Interesting idea.
Like the first video points out, plastic breaks down and flakes all over. A wooden tray with soil blocks and possibly a cloth wicking watering system sounds much better. I'd really like to hear more from people who have used soil blocks.
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