Here we have a half-tray of cabbage and a half-tray of brussels sprouts planted in soil blocks.
Chris made these soil blocks, and they are exactly what they sound like: blocks of soil in which you plant seeds. We ordered a Soil Block Maker from Johnny’s Selected Seeds, and have been trying our hands at this plastic-free method of planting seedlings. With about a thousand seedlings that need to be started before the garden is tilled (!!), these should save time, space, and headaches.
These blocks are made out of mostly a soilless mix that we got from Morning Sky Greenery, and also some plain old “dirt” which helps the blocks hold together. Peat moss, vermiculite, and perlite gets a bit too crumbly when it dries out, so we had to add some dirt to the mix. We also added a bit of lime to help balance the pH (as peat moss is quite acidic). Most things we’ve read say to mix fertilizer and compost in with the soil block, but we have no fertilizer at this time and our compost pile that froze over the winter is slowly, slowly working. So we made some manure/compost tea, which we’ll start watering our seedlings with once they get their first set of true leaves.
It’s a really simple idea, and a simple machine makes the blocks. Soil blocks are spaced with just a bit of air between each block – the plant roots stay in their own block and don’t cross the air gap into the neighbor block. If you’ve ever bought annual flowers from a department store greenhouse before, you know how terrible it seems to rip root systems apart to separate your flowers for planting. The soil blocks are supposed to reduce transplant stress as well.
Once the roots fill the entire block, the blocks get placed into the center of another block of soil, which is made using a larger hand-held machine. We’ll have to do this with some of our seedlings, but many can probably stay in the 2″ block until they are ready to be planted outside.