Soil blockers are a great way to start seeds for your garden, but some of the soil blocker recipes you’ll find around the web aren’t exactly sustainable – including things like peat moss and artificial nutrients.
I’ve tried to take the general ideas from other recipes, and make a more environmentally-friendly soil blocker recipe mix. The main change is to use coconut coir instead of peat moss. It provides similar water-holding ability, and has coarse fibres that help hold the blocks together.
My Soil Blocker Recipe
- 2 compressed coir bricks, expanded in water as per directions (makes ~20 L volume)
- 5 L worm castings from the worm farm
- 10 L sieved compost from my compost heap
- 5 L clean sharp sand
- 2 handfuls of garden lime
- 2 handfuls of rock dust
Mix it all up thoroughly in a wheelbarrow, adding water to keep the mix nice and moist. It really needs to be fairly wet to form nice blocks.
Once mixed, plunge the block maker into the mix and squeeze the blocks out. Lay the blocks out on wooden boards or in potting trays. After planting seeds in them, I put them on shelves in a little mini-greenhouse to keep them warm and moist.
From these quantities I get a bit over 150 of the 2-inch soil blocks.
Other Soil Blocker Recipes and Resources
Here are some other resources for making soil blocks:
- Soil Blocking eBook – really awesome free ebook from AllSun, with lots of details including commercial soil block use
- Allsun.com.au – recipes for soil blocking mix, plus lots of good photos and tips for using the blockers
- PottingBlocks.com – recipes for soil blocking, plus look around the site for lots more information on soil block use
- Another soil block recipe
- JohnnySeeds soil block maker info sheet
If you know of any more soil blocker recipes or tips, please post them in the comments below and I’ll update this list. Thanks!