Barbara Damrosch and Eliot Coleman are spouses, writers, and farmers who have been advocating for sustainable growing practices since the 1970’s. As we’ve investigated small scale farming, I quickly went from not knowing anything about them to referring to them casually by first name. For example, “Shouldn’t we try making soil blocks like Eliot?”

Coleman is strong advocate for growing seedlings in soil blocks rather than plastic celled seedling trays. Once the roots begin to run out of room in a container, they will start circling, creating a tightly bound mass and stunting the plant’s growth. But if you create blocks of soil from a mold (i.e., no walls!), once the roots run out of soil and hit the air they pause and wait for more soil.

We thought we should give soil block making a try since transplanting large healthy plants will be important for our high intensity, no-till model. We also love the idea of using less plastic.

Step 1: Purchase a soil block maker

We’re trying not to acquire farm equipment in our 1-bedroom condo but it seemed important to get some practice with the soil block maker so we went for it. We chose a standing soil block maker that makes 6 big blocks at a time. You can make tiny soil blocks and then transfer them to a bigger block with a perfectly sized insert for the small block. But all that transferring seems fussy and unlikely to be time efficient on a commercial scale.

Step 2: Create a good soil mix

We combined potting soil, seed starting material with coconut coir, and castings from our worm bin. Adding coconut coir (coconut fiber) or peat moss is important for a soil block mix since these amendments create fluffy soil with a good texture that can absorb a lot of water and hold its shape. Peat moss plays an important ecological function in bogs and is often over harvested so we chose to avoid it.

Step 3: Add water

This step seems so simple and yet it took us a long time to get it right. All of the YouTube videos we watched said to aim for brownie batter texture but we found that less water and more coconut coir was needed to get our blocks to stay together in the soil block maker.

Step 4: Make soil blocks

I’m hoping that practice and a good soil mix recipe will speed this up our rate of blocks/minute. We definitely improved our packing technique as the afternoon went on – having a lot of soil in our mixing container was key. Coleman will throw his soil blocks in the air to assure people that the blocks don’t just fall apart. I don’t think ours could withstand that test. Maybe next time 🙂

Step 5: Plant!

We started our seeds in the beginning of August and have had them indoors under lights. We’ll plant them outside before the end of August and hopefully have kohlrabi, cauliflower, turnips, and beets throughout the winter.

I don’t know if soil blocks will work for us once we start our own farm but our first try at making 24 soil blocks didn’t dissuade me. I’ll let you know how it goes when we have 1000’s of blocks to make in March!