I am using a new method this year for growing transplants for the garden.
This is called a soil blocker. It has twenty 1/2 inch by 1/2 inch soil blocks.
You push the block into soil. I used Fort Vee Light from the Vermont Composting Company (not sure on the name of the company and I'll double check that later). It needs to be pretty moist to work well and I found that it worked even better if I pushed the soil into the compartments with my hands. You them put the blocker in your tray and push down on the top piece and pull up the block.
The result is that in a regular sized flat you can get 300 (if all are perfect) little pockets to start your seeds. The benefit is that if you are growing them on top of a seedling heat mat and using lights to aid in germination, it would take you 4-7 trays for the same amount of seedlings with regular sized starters. The square design also aids in root growth. The roots grow out instead of in a circle which happens in typical starting systems. Because the roots also have no boundary, they take root quicker when placed into the next soil block or into the ground.
I found that the best way to cover the seeds was to put some more dry soil on top of the seeds and then mist the tops with a spray bottle.
Once you've got a germinated seedling, you then use the bigger 2 inch by 2 inch soil blocker and you place the 1/2 transplant into the center of the 2x2 block. I have not done this step yet, but I'm getting close with my onions that I started last weekend. At the point that your seeds are germinated, you can then move them to an area that doesn't require a heat mat and you can use a little less direct lighting. I have to figure out where I am going to put all my 2x2 sections. I am using the basement right now but I'm going to need to reorganize and clean up the counters as I will need a lot of counter space. And I mean a lot of counter space- thankfully the basement work area has a really nice setup. Next year I hope to have a greenhouse so it will make this so much easier, but for this year I'll need to deal and work with what I have.
Here are some of the onions starting to come up. I found that the side areas were staying nice and moist but the center blocks were drying up. I am now misting the center blocks with a spray bottle of water once a day and more of the seeds are germinating.
The entire process for 1 completed tray takes me about 30 minutes at this point but I think the bigger blocks will be a faster process. I enjoy the quiet work of seed starting-- to me it's very calming.