BLOCKING MIX RECIPE From The New Organic Grower, by Eliot Coleman
A standard 10-quart bucket is the unit of measurement for the bulk ingredients. A standard cup measure is used for the supplementary ingredients. This recipe makes approximately 2 bushels of mix. Follow the steps in the order given.
3 buckets brown peat (standard peat moss, use a premium grade)
1⁄2 cup lime. Mix ingredients together thoroughly.
2 buckets coarse sand or perlite
3 cups base fertilizer (equal part mix blood meal, colloidal phosphate, and greensand). Mix.
1 bucket garden soil
2 buckets well-decomposed compost. Mix ingredients together thoroughly.
Sourcing out these individual items this time of the year is difficult. I checked the ingredients of seed starting mix and found it was made from approximately 80% peat moss, 19% perlite, 1% lime, and a wetting agent. So by adding some compost and using some balanced fertilizer, I am hoping to be close enough to the original recipe. I would probably be ok with most potting mixes too if I screened out the larger pieces. They usually are made from composted forest products, peat moss, perlite, and fertilizer.
I gathered my materials on the workbench in the basement which will now be my seed starting area:
I’ve been saving plastic produce and bakery containers to use a mini humidity domes:
First I added some hot water to the seed starting mix and let it sit for a while so the peat could absorb the water:
Then I added a few handful of compost and mixed well until it seemed to be the consistency of wet cement:
Some water oozed out when I squeezed a clump of the mix together like the instructions describe:
I filled the soil block maker by first mounding the mix, then pushing the blocker into the mix firmly until it reached the bottom of the container. Then I twisted the soil block maker, lifted it up, and scrapped the excess soil level with the soil block maker:
Then I moved it to the container:
And squeezed out the blocks in a neat row of four 2x2 inch blocks:
Some turned out better than others, but any rejects were just plopped back into the mix:
Twelve blocks fit snuggly in these repurposed salad containers:
And eight in this one:
All stacked up and ready to seed: