Of course you can't really make free soil blocks without making free soil. Our next subject will cover the art of blending your own soil block mix soil, for free, without the need to purchase anything.
Someone once said "Necessity is the mother of all inventions.", well, when I needed some blocking mix, I invented some right on the farm. It was really more about experimenting with on-farm materials until I came up with the right stuff. From those experiments, I figured out how to keep the free blocking mix coming so that it was always there. If you want to make free blocking mix, first, you have to discover what you do have. Blocking mix, in my experiments, need to have at least 3 parts fibrous material, 1 part drainage and/or aeration material, and 1 part compost, and a little nutrition/sweetener. Let's break down these elements into what you might find at your place:
Fiber (to knit your blocks together) is normally purchased in peat moss. If you have a peat bog in your back yard, dig some up and tell me about it. Here, in western Oregon we are blessed with a type of moss that lives on fir branches and the forest floor. It is very similar to peat moss, in fact, it is a moss and works just as well. You might have seen it lining hanging baskets. It's a light green, soft and very fibrous moss. You can dry it and crush it up a bit to make your own home-made peat moss. If not, the next best thing is chopped straw. It contains a nice light texture when chopped and sifted so that it knits together with the addition of compost or some compost/soil mix. Provided you have some dry straw, crush it up and sift it over a wheel barrow with some 1/4" screen. No straw? No problem, how about hardwood mulch or saw dust or hardwood branches that were stacked up and dried in a brush pile? Crush the brush pile and sift out the little pieces with your trusty, "wait for it", 1/4" hardware screen. Same with the mulch or saw dust. I really only recommend hardwood, as it is not so acidic and it doesn't inhibit germination. The best fiber from hardwood is a big hardwood pile of mulch or chips that have composted and are dark colored. Look around the neighbors yard, too. You or your neighbor will also have the next fibrous material, leaf mold. Leaf mold is decomposed leaves that still have some structure or leaves in it. It is known as "mold" because of the beneficial fungus that eats and lives in the nutrient packed leaf. Make sure it is also dried out a bit, crushed and sifted over a "you-know-what". These are the best ingredients to use, but if they are still not available try dried, brown, and fluffy grass clippings. Feel them, are they loose, dry, brown, light, not sticking together? You could make this material by bagging your own clippings and then sun drying them until they are crispy. Try dried, black pine needles under a fir, pine or spruce tree. They have to be black and dried so they will not cause major problems with your plants, like over acidity and numerous other problems that I urge you not to discover. Do you shred your own paper at your home or office. Bag it up and take it home. However, leave the little plastic window pieces from the envelope in the trash. O.K. then, I know anyone can have fiber around their house somewhere. Let me know if I missed any material.
Drainage and/or aeration material normally comes from perlite and vermiculite and is used to drain away excess water and provide air to the roots. It is also used to store a little water for the dry times of waiting for the next watering. By far the best material is sand. Sand from the beach, sand from the dunes, sand from your kid's sand box(don't take it ALL!). Sand is free everywhere and needs no explanation other than don't take it from potentially toxic places or sand that is too salty from high tides. Go a little bit further inland and it will be salt-free. Some people have it and some people don't. I have had it only once when we were mixing cement, and used some extra in my blocking mix. I really liked it, but since, have not used it, as perlite has been so cheap. Now, I'm ready to go back to sand, as it weighs down your blocks a bit for the outside transplants that get hardened off in the elements. If sand is not around, and sometimes I know it isn't, try rocks, pebbles, pea gravel, river stones, etc. screened through 1/4" screen. Go easy on the screen by using small shovel fulls and sifting slowly. Rocks should be everywhere and should come from a safe, non-toxic area. Volcanic rocks are best, especially pumice stones. All I've got now are basalt gravel and it's not my favorite because it's sharp and heavy, but screened and washed(driveway gravel) makes a most suitable free substitute. Do you have pine bark from ponderosa or yellow pine or jack pine or black pine trees? Crush it up, sift it out, wash it down, and it makes an awesome aerator. I only recommend the thick pine barks and not fir or spruce as they are much more acidic and difficult to grow plants. You could, however, compost them first, and use them when they are black. So, somewhere, someone will have these three on hand: Sand, Rocks, Bark. Now, it time for compost, and we have all heard it before: the best compost is dark and crumbly, finished, mature, smells aromatic, aged, broken down and homogeneous. Great compost is the key ingredient. See www.pottingblocks.com/compost.html for a primer and a how-to course. Our final ingredient is a little nutrition and sweetener. Your mix might be a little acidic from some of the ingredients we get on our land, so it's best to sweeten or alkalize your mix up a bit. Do you have any old sheet rock around? Crush it up, remove the paper and sprinkle some of the dust into the dry components like the fibrous material first. This is in essence, lime, gypsum lime to be exact. It may not be safe, as some drywall has asbestos in it. Use caution. The next sweetner is a little hardwood ash from your wood stove. Use only pure ash from hardwoods and nothing else. Sift and blend with the dry ingredients. If your soil is made with straw, and you're growing brassica family or Cole crops, dried and crushed eggshells will improve conditions considerably. Live near an ocean? Pick some sea shells and oyster shells and crush them up and add them to the dry mix, too. Do you have animals? Do you feed them alfalfa pellets or hay? Crush those up for a base fertilizer. Wow! We are on a roll with all of our free stuff. We better get a recipe and get mixing, there's still time you know? See www.pottingblocks.com/recipes.html for the right proportions you'll need to make a free blocking mix. Let me know of anything I may have missed or email me with any question. The whole point is to get growing using Nature's lead as our role model. Everything in nature grows just fine with free materials, why can't we? Just mimic our Mother Nature and we will succeed. Stay tuned for the most interesting subject yet, home made soil blockers. Come again in the guru's potting shed!