Thursday, August 21, 2008
Environmentally Sound Potting Soils for Soil Blocks
Many of our readers are sharing their concerns about the enviromental impact of horticulture grade potting soil materials, not to mention the possible irritants of mined products. So, PottingBlocks.com has made a new commitment to provide detailed information about new environmentally sound and healthy-minded potting soil ingredients. But first, a clarification: Potting soil contains soil or compost or living ingredients. But, then it could be sterilized and become inert. Always know what has been done to your potting soil. Then, you have potting mix. Potting mix or potting soil mix is always inert, and always free of soil, or known as soil-less. For the most applications, your blocking soil is a potting soil, or, full of soil, compost and never sterilized. Now, back to the point...Peat moss has come under attack, as of late, because of environmental degradation of peat bog ecologies. PottingBlocks.com has responded with test runs of coir fiber from some companies that are milling it just right for soil block making. Suprisingly, most coco peats will not work for soil blocks without half peat moss. We are almost ready for release of the first and only soil block recipe with only coir. In the past, I have always recommended peat or coco peat mixed half and half. That is because soil blocks must knit together and yet still be friable. Peat moss has been our only medium. But, with certain techniques, coir can be washed, aged, composted and milled exactly like peat moss, so hope for the future is here! We will be updating everyone when we have the coco peat moss line available. If you have access to straw, like wheat, barley or rice straw, the kind with the hollow stem, you can shred it by hand, or leaf shredder, and sift it with a 1/4" soil sifter. Use it as the same ratio as peat moss. The key here is to use soil and compost in your block mix to bind it all together. It will be friable enough for seed germination. As, far as human health is concerned, perlite has been known to cause certain irritation in some people's throats and lungs. Perlite lets off a lot of dust when dumped and mixed, so ALWAYS WEAR A DUST MASK! Mining products are still a key component to horticulture, so at the present, the next best alternative is PUMICE STONE. Pumice stone is mined from abandoned, open field, lava and volcanic ash wastelands, so it's impact is minimal. I can find it for less than $50 a ton, and is a very suitable replacement for perlite, with no toxic dust! This is a miracle product that I wish I was using years ago! You might be able to find it by the bag, but, maybe you should call or go to a nursery and see if they can bag you up some. The next concern is vermiculite, which is a known carrier of asbestoes, IF IT HAS NOT BEEN TESTED! Always buy "tested for no asbestoes" vermiculite. The best suitable replacement for sand would be large, coarse, washed horticulture grade sand. It may not help moisture retention, as water usually drains freely in sand. But it does work, if you keep your blocks well watered. You must, however, use the coarsest sand possible so your blocks do not fall apart. Sand harvesting, as you might expect, does minimal damage to the environment. We will keep you updated as soon as our test results are complete to which materials we should all be using to save our beautiful, abundant planet. Also, we will be releasing our line of Vegan Composts, Vegan Worm Castings, and Vegan Fertilizers and Amendments, as well as our commercial line of ready to use blocking mix called Old Farm Boy. Stick with the guru, I promise to protect the environment!
Posted by Jason Beam at 7:10 AM