I have heard that many people bought soil blockers through the years, and then, stopped using them. There are numerous complaints as to why they won't bother with them again. This has come about due to the lack of authentic information at the time of purchase, and misguided information from garden forums on the web. Results from your soil blocker should always be excellent. We have covered the basics for a successful experience at www.pottingblocks.com. However, should you read this before you buy, or before you begin practicing the art of soil block making, as you will be far ahead of the learning curve. Once you know what NOT to do, maybe all that's left is the right way to soil block, and any further discussions, or shall I say, speculations, on garden forums on the web will end. Here is my top ten list of the biggest mistakes made, most common errors made, or beginner busters that need to be avoided. Let's count down to the biggest mistake. Oh, and on a positive note, the only way we learn is through our mistakes. So, thank us later, those who have come before you and learned the craft of soil block making.
Number 11. You don't wet the potting soil enough, or you water it down too much. Your striving for the consistency of oatmeal. You would want to pick up a ball of mud and sling it on a wall and there it would stick. You want your blocking mix to be wet, yet only drip when well squeezed with your hands. You are looking for stiff wet mix, yet you won't see any water puddling. The soil should easily stack up in your bin. Keep churning it, and adding water to wet, or more potting soil to dry.
Number 10. You don't dip your soil blocker in water after every discharge. Dipping is essential to wetting the machine and allowing the next round of blocks to eject smoothly.
Number 9. You don't screen your potting/blocking soil with a 1/4" screen. This is essential, as particles larger than 1/4" will clog the simple moving parts in your blocker. This causes the blocker to eject a crumbly erratic block.
Number 8. You don't charge, or pack your blockers with enough soil. Don't be afraid to pack that soil in the mold. How else is it supposed to hold up to watering and root growth without a pot to contain the plant? You cannot overcharge a soil blocker. This is why it was created: To hold 3-4 times more soil than a loose filled pot of the same dimensions. The roots will penetrate the soil easily, provided you made your own potting soil. See recipes.
Number 7. You don't cover your seeds with a sheet of black plastic, or sift more potting soil over the top. Unless your seeds require light to germinate, always cover with black plastic or sifted potting soil to anchor your seed in the block and mimic natural conditions, like moisture and darkness. Be aware that a vital seed will sprout very fast under the black plastic, so check every day.
Number 6. You don't use a thermostatically controlled heat mat. How else are you supposed to trigger the seed to sprout if you don't give it a perfect soil temperature 24 hours a day? In nature, the soil on the ground serves as a heat sink or bank and can retain that constant temperature. Not so in blocks and pots. You must provide the minimum heat requirements.
Number 5. You don't tilt, lift and twist off the bottom of your mixing bin to release the suction and pull off a clean and smooth bottomed soil block. This is certainly the trickiest trick to soil block making. If you don't tilt, lift and twist your blocks will get stuck in your bin over and over, or fall out prematurely, or not lay flat in your flat. Be prepared to practice a few times, if this is new to you and allow some trial runs.
Number 4. You don't use one hand with the Micro 20, 3/4" soil blocker. Try using one hand and pack and pack and pack the soil blocker until it is so compacted that the bottom looks like one block. Then, DON'T SCRAPE THE BOTTOM. Scraping the bottom of the Micro 20 is counter productive and ruins a good block. But, make sure it lays flat in you flat.
Number 3. You don't mist your blocks. How else are you supposed to deliver oxygen to your roots unless you "mist" them and oxygenate the water as you water your blocks? Mist mixes with air and light as it is soaking your blocks. Misters are easy to find and are the life blood of your plant roots. If all you have is a watering can, at least fill it up using a squeeze trigger nozzle and really, really agitate the water so it gets real foamy and bubbly. This aerates the water and delivers oxygen to your roots.
Number 2. You don't water them enough. After your seeds sprout, they'll need water three times a day if you use a peat moss based soil. Less, if it has coconut peat, and even less if it has water absorbing crystals in it. That's why it's important to know your ingredients. Bottom watering is helpful, but are you aerating your water with an air bubbler? Remember, you must actively aerate your water for your blocks, unless they're planted at the edge of a rushing stream!
Numero Uno. You don't use the right potting soil. You must make your own and in the correct proportions. At very least, you have to experiment with store bought brands. Potting soil and mixes were never meant to be used in compression machines. They were not formulated to allow water to penetrate while being compressed. They were not mixed with the right volume of peat to compost. They may not have enough aerator and moisture retaining ingredients like perlite, diatomite rock, or pumice. Or, the particles are too big. Or, the compost was made with forest by-products. Or, there was no long term fertilizer. Many people believe that all potting soils are the same and should work with their new blocker. All potting soils are not the same, and must be tested in order to see if they're compatible with the soil block machine. Some say that mixing their own is too much work, or they can't find the right ingredients. You can always buy the "Old Farm Boy" potting soil, which is specifically formulated for soil block makers, but is used by everyone. Because, while all potting soils can be used for containers, only one brand can be used successfully for block making. You simply have to mix your own if you want real great results.