How to Make Soil Blocks

Soil blocks have been around for a number of years and are a great alternative to using plastic cell packs. Once the seedling is ready to be transplanted, the entire soil block is planted directly in the soil which helps to lessen transplant shock. Once you buy the soil blocker and planting trays, the only recurring cost is for the potting mix. Here's a short post showing how easy it is to make soil blocks.

The soil blocker shown below is the Ladbrooke 2" soil blocker. There are smaller and larger soil blockers available, but the medium-sized one is working out just fine for our needs. They make special soil blocker tubs, but you can use any kind of tub as long as it's waterproof. The one shown below is just a small (10" x 15" x 6") storage container from Lowes.

soil blocker tub

How to make soil blocks:

Begin by filling the tub about half full with potting mix. Add enough water to the potting mix to make it wet. Not damp and not soaking, but it's better to err on the side of too wet than too dry. The key to making successful soil blocks is compaction. If the potting mix isn't wet enough the soil blocks won't hold together and if they're too wet it's a mess to work with. Once you have a good consistency, fill the soil blocker either by plunging the soil blocker into the potting mix and twisting it into the pile, or just shoveling the mix in by hand. Whichever way you choose, make sure the soil blocker is well-packed. Remove any excess potting mix so the bottom of the soil blocks are flat.

soil blocks filled with potting mix

Hold the filled soil blocker fairly close to the seed tray so the blocks don't have far to fall. Pull up on the bar with your fingers while pushing down on the lever release with the heel of your hand. The soil blocks should come out easily. If not, it's no big deal. Just put the broken soil blocks back into the tub and try again. If you loaded the soil blocker by hand the first time, try the plunge and twist method and vice versa, or maybe add a bit more water to the potting mix. You may need to rinse the soil blocker after making a few rows of blocks depending on the makeup of your potting mix.

putting soil blocks in seed flat

That's it! That's all there is to making soil blocks. Keep going until you have as many soil blocks as you need. Add your seeds, cover the flat with a plastic cover until the seeds sprout and you're all set. You shouldn't need to water the blocks for a couple of days depending on how warm and humid it is. Be sure to check frequently though because soil blocks end to dry out slightly faster than potting mix in plastic cell packs.

finished soil blocks

How to make soil blocks video:

Here's a video version of how to make soil blocks: