6 Quick Steps to Soil Blocks
- Empty bag of potting soil into tub, setting a little aside in case you make your mix too wet on your first try. (Sift for ¾” blocks)
- Add water, stir, and wait one hour for it to soak in. If you don’t have the time, then be sure to stir very thoroughly. Add enough water to give it a thick peanut butter consistency. Too watery and the mix won’t form blocks, too dry and it won’t go in the blocker. Trial and error are your best teachers.
- Thrust the blocker into the mix 2 or 3 times to fill the chambers snugly and smooth the bottom of the blocker against the bottom of the tub.
- Set blocker into tray, lift up with your fingers on the handle while depressing the plunger with your thumb ejecting the blocks straight up.
- Place the next set of blocks 1/8” away from the previous set to make an air root pruning gap. (Dip in water to clean out soil in blocker)
- Wash and dry the blocker after making blocks. Otherwise, the natural acids in any growing medium will corrode the protective zinc coating.
- Do not use potting soil that has decomposed or “composted” wood chips or wood by-products in them. We have had poor results on our research farm. Regular Miracle Grow potting soil is the most commonly found potting soil and it works great in soil blockers. Happy Frog is good organic potting soil. Be cautious of steer manure in soil blocks, as they could give below average results.
- Micro 20, or Hand-Held 20 soil blocker maker makes 20 ¾” cubes: Use one hand or two hands, depending on the size and strength of your hands and fingers. Use gently, but pack soil firmly to create nice seed holes.
- The bottoms of soil blocks should be flat in order to sit straight. Smooth the bottoms by rubbing them back in forth in the bottom of the tub or you can scrape off the excess on the side of the tub. Tilt and twist off the bottom to release the blocks from sticking to the bottom of the tub after filling the blocker chamber.