Friday, January 23, 2009

Finding the Fabled 8" Soil Blocker.

I've noticed most gardeners use the 2" block maker. And, only a few commercial gardeners use the 4" block maker. Maybe it's too heavy, maybe it's too much work, maybe it uses up too much potting soil, or maybe it's too expensive. Some will make their own 4" block maker. But, not me. I have covered why the 4" Ladbrooke block maker is the King. For those that do use the four inch block maker and are curious if it can be potted onto another block, you have arrived at the right place. I call it the fabled 8" soil blocker because nobody makes it, you have to make your own. And, besides, I don't even know of anybody who has ever made one! Why would any body do that? It's true, it brings up a lot of questions, doesn't it? Well, let's take a look at the nursery business. How many sizes of plastic pots do they go through before the final sale? Lots. We're starting to seed in November for summer block sales. We sell mostly soil block six packs in recycled wooden flats. When it's time for larger pots, I reach for the black plastic bags in 1-10 gallon sizes. I use bags because I anticipate the customer throwing them out when they've transplanted their plant. It has way less waste then pots, way cheaper, and way lighter, easier to move, and has a slight square shape, which we all know from soil blocking, saves space. But I'm all about the reduction of plastic pots on my farm. So, one day I decided to build my own 8" soil blocker. Out of new plywood and hardwood dowels and an old metal spring and some short screws came the invention so few will use, so few will need, so few will want. Oh well, I loved it. It worked. It worked just like the 4" block maker. It makes a BIG block. Now, I could transplant long standing plants like blueberries and all of the berry bushes in 8" blocks. I could keep fruit tree saplings around a year or two now with no worries. I could over-winter peppers. I used them for landscaping plants and hedges to roses and flowers, flowers, and lots of blocks of flowers. My next challenge was to provide a way for my customers to cart off their blocks. This block is heavy, like about 5 pounds of wet potting soil, so if it falls, it breaks. Other than that, it can be made out in the nursery and just sit there. With the right blocking mix it was easily moved, but that was also a challenge to find the right blocking mix consistency. And, although I could move it with a wide tined manure fork, I know my customers needed a handle. So, with some left over jute netting, which is similiar to burlap, I sewed a cradle/sling with two handles slightly offset as to not disturb the plant stems. I used some thin hemp twine and a long nail punch and made a very inexpensive reusable sling for easy pickup. Now, it's even better with constant refinement. I build the block right on the sling, or sometimes in four packs with custom slings for blocks of berry bushes or peppers. Much like the wooden flats for 2" six packs, I offer the customer $1.00 off their next plant of the same size if they bring the sling back. Was all this extra work really necessary and worth it? Absolutely! I have a customer base that shop at my garden center because it's different. I keep giving them reasons to support me and spread the word about my offerings and commitment to the environment. With all of this oil talk, I can offer the customer an environmentally alternative to ugly plastic pots, and entice them to come back with the $1.00 "deposit". What are the difficulties in using the "fabled 8" soil block? First, it's heavy. It requires great strength to make a block. Second, it requires a lot of potting soil and a large tub. It has to be deep enough, like twice the size of the depth, which is 8" for the depth as well as 8"x8" on the sides, and enough room for the long charging handles. Third, you have to make them where they will sit for up to 3-6 months or a year. That takes a lot of planning. For my nursery, I use mobile tunnel over landscape fabric to keep them warm in the winter and slide the tunnel off of them for outside summer sales. Fourth, for commercial use, you need to sew up some slings. That is very time consuming to sew up hundreds and in a couple of years, tens of thousands of slings. Fifth, building the blocker so it can withstand repeated use is slightly difficult. I have had to rebuild mine a few times already. Wood and screws cannot keep up with the demand on this machine. I am having one constructed by a metal fabricator starting this year. Email me at if you're interested in purchasing one. I am not sure if there will ever be a need for one outside of my unique nursery, but I am here to say that all the principles of soil block gardening are used to create the 8" block and it is well worth it. Here is one design (next paragraph) based on my experience with adobe and rammed earth building. It is so easy to build and easy to use, perhaps this is the idea waiting for discovery.

You'll need: a couple of 2x 8's scraps and some 2 x4 scraps, some 3" wood screws, and a cordless drill. Build a frame with the 2 x8's as long as you want, but preferably the lenth and width of at least a four block maker(21" x21"). Frame the interior of that wood block with cross blocking keeping your 8" square and creating 4 squares. Done. Now, set it on a piece of plywood and water it down really wet. Next, make up some blocking mix with whatever you've got. Refer to my blog on making free blocking mix for ideas, entry for May 11th, part 3. Fill it halfway with a moist layer of mix, but not as moist as regular blocking mix, as you'll want to tamp, or slightly tap the potting soil down with a block of wood. I use a four by four post end cut off and attached to an old wooden handle. Moving on until you reach the halfway point or 4", then build a stack of 2 x4's 3 high(4 1/2") and 4 1/2" inches long. Screw 'em together and you've got your cubic pin. Screw a little block of wood on top in the shape of a handle so you can pull it out later. Water the pin down, too. Lay that in the center and make sure that the cube is flush with the top of your form. Fill with tamping mix around the block and begin tamping and filling until you've reached the top on all four blocks. Now, carefully tap around the outside of the form to release suction. Pull up the form carefully. Note: This is different for every type of wood used. Some woods may catch on the blocking mix and some won't. To be absolutely sure it comes up clean each and every time, do one of these two things: 1.) Sand and paint the inside with Kilz latex primer. Or, 2.) Let your form and cubic pin soak in water for a couple of days in the sunlight and let it get all slimy with algae. I recommend the soaking to get the algae growing because it's natural and easier and slicker. In this case, you must use galvanized 3" wood screws so they won't rust. After the form is pulled off you should have four beautiful blocks. Now, carefully grab the handle of the pin and lift straight up and out. Voila', you're Fabled 8" block is ready to use. Stuff it with your favorite 4" plant and move it in part sun and part shade for a while, and water well in a couple of days with some manure tea. It can sit there virtually all season without the need for transplanting any further, if you fertilize regularly. Transplant late in the season if neccessary, but only in late afternoon. And, if you want to keep this block idea going, make yourself a 14-16" block the same way and Pot On again. You know I will! Blast me email if you've ever tried to Pot On your 4" block. I'd love to hear it, but you know that! The Guru writes again and everyday until the world understands the soil block method. The Guru predicts the wave is coming. The Guru understands the power of relentess pursuit of passion! Au revoir!

Wednesday, January 14, 2009

Environmentally Sound Ingredients 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, 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. 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!

Sunday, January 4, 2009

Moisture Retention in Soil Block Ingredients

You know you'll have to make your own blocking mix in order for your blocks to be perfect and professional. You know your main ingredient is peat moss. Your next ingredient is the water absorbing, retaining and aerating medium known as the fluff or the fill. It puffs up the peat which will be saturated with water. Yet peat would dry out too fast if it wasn't for the fluff. Typically, this material has been known as perlite. And, just as peat moss was the only way to make blocks until coco peat came along, perlite was the only way to hydrate and aerate your blocks. Not so anymore. There are now two more exciting mediums to consider, if you have access to them. The first is pumice stone. By far the cheapest ingredient to add to your soil block mix if you can get it local. Pumice stone can absorb and release anywhere from 45-65% of water back to the plant roots. Perlite can absorb and release only 35% of available water, still too low to prevent drying out in case you skip watering for a few days. But with pumice, you have less to worry about, and it is not dusty and irritating to the lungs, which is one drawback to perlite when mixing your own. Pumice is common out in the west, I get it 25 miles away at 50.00 bucks a ton! Cheap! You may have to screen it down to 1/4" before mixing, as it might plug up your blocker. Pumice is the best replacement for perlite when budget is a concern.
The next ingredient of monumental importance to our potting soil industry is diatomite rock. A mined substance from ancient sea bed dwelling creatures, diatomite rock is diatomateous earth before it is pulverized. The new king in organic water retention, it has the ability to hold 150% of it's own weight in water and slowly release it back for absorption by the plant roots. Not only that, it is less dusty and contains numerous micro minerals and nutrients. It is also very colorful in all shades of pastels. Makes a very pretty potting soil! It is a little more expensive than perlite, but well worth the cost, if you forget to water in the heat of the summer. It will not dry out for many days, whereas perlite would be spent of its water and the plant will be dead. Diatomite rock is as lightweight as perlite, too, yet breaks down in your garden soil even more slowly, releasing valuable trace minerals.
And, of course, those seeking a fool proof addition to the blocking mix and any of the three aerators mentioned, Zeba Quench will be mentioned again and again by myself and other commercial farmers. Zeba Quench is an all natural, starch-based biodegradable super absorbent soil amendment that improves soil moisture retention and water supply to plants. It can deliver up to 400%! of its weight in water back to the plant. And, Zeba Quench releases 95% of its stored water to the roots when they need it most. Not only can it do all that, it can do it over and over for hundreds of times hydrating and re hydrating the plant roots all year long. Decreases your watering by 50%, which is a lot of time spent frolicking somewhere else in the summer, not slaving over transplants. It is the ideal soil block amendment, and it comes recommended for no other reason than the assurance factor of having reliable transplants in all seasons.
Many people are reluctant to buy Zeba as an added expense to what should be a virtually free act of gardening: starting and transplanting seedlings in soil blocks. I understand. But, Zeba is most helpful for beginners, busy careers, moms and busy housewives, and professionals in the nursery business. Why? Because if your not always right there tending your soil blocks, they will soon out grow everything around them and be searching for more water, not more space. In a moment's notice, the hot summer sun could kill thousands or even just one precious transplant. If you know you can't be there all the time to monitor soil block growth, which, literally grows before your eyes, than hire someone that will. That help, my friend, is Zeba Quench.
But remember, you can always skip soil blocking and keep your plants in a stunted state of existence called: Plastic pots!
Good day and welcome to spring, the Potting Block Guru is here to dispel the darkness of winter blues! Stay tuned, onions are coming up!