Step 6: Soil Block mix

3 buckets brown peat (standard peat moss, use a premium grade)
1/2 cup lime. Mix ingredients together thoroughly.
2 buckets coarse sand or perlite
3 cups base fertilizer (equal part mix blood meal, colloidal phosphate, and greensand). Mix.
1 bucket garden soil
2 buckets well-decomposed compost. Mix ingredients together thoroughly.
* From The New Organic Grower, by Eliot Coleman

Or you can use any good organic potting soil. I found a bag of Master Nursury Gardener's Gold Organic potting mix and it works great. I did make my own blend as above too, but it was expensive and time consuming trying to locate greensand, colloidal phosphate (gave up - could not find), etc.

Add 1 part water to 3 parts soil mix. Mix to a soft putty or wet cement (not soupy). A soil block needs to have the soil packed tight. Rinse out blocker in bucket of water after each block is made. This will help release each new block made.

Remember that soil blocks can dry out faster than soil in flats or pots. Keep an eye on them. Good luck!
<p>Awesome work...if your not good in wood working, you can also use a small round sardines can...open the top with <br> a can opener, keep the round piece to use later or make a plastic round piece <br>or look for a washer which would fit in the sardines can and drill a <br>hole in the other end, insert a threaded carriage bolt and a spring(optional) and <br>voila...round sardines can soil block maker</p>
The soil touches the PVC for like 5 seconds when making a block.&nbsp; Even it touched it for 5 hours it wouldn't off gas enough to introduce anything in the soil that would be harmful.&nbsp; Then if it did, the chances of the plant absorbing that and it getting back to you is probably nil.&nbsp;&nbsp; <br />
I wonder if there's a special purpose to the pvc part of this? Such as being smooth so the soil won't stick? The reason I wonder is that I'd like to make a 4" soil blocker to accommodate my commercially produced 2" soil blocker which makes square blocks. We have a farm and square is nice since we do thousands of starts and the squares fill a large flat without wasting space. The commercial 4" blockers cost $100! We might have to go back to using plastic as our tomato and pepper starts get bigger unless we can figure out a functional design for a large square blocker. Ideas and suggestions much appreciated! Thank you!
If I were looking to make 4 inch square soil blocks I would look at square pvc such as plastic down spouts and pvc post covers uses with pvc fencing.
YES, PVC fence posts also come in 4&quot;x4&quot;, but several things to consider:<br /> <br /> Most pvc products intended for outdoor&nbsp;use,&nbsp;including&nbsp;fence posts, contain&nbsp;LEAD which is used as a stabilzer/UV&nbsp;inhibitor.&nbsp; &quot;country estate&quot;&nbsp;brand PVC&nbsp;fence products, made by Nebraska Plastics, is the only one I&nbsp;know of which is lead-free.&nbsp; <br /> <br /> All plastics are known to off-gas and to leach chemicals, as noted in prior posts.&nbsp;&nbsp;<br /> <br /> PVC&nbsp;fence&nbsp;components&nbsp;are typically rather thin and will not hold their shape with heavy use as well as aluminum.&nbsp; The exception is the HD&nbsp;gate post that some mfrs (such as CE) offer, which are available in 4&quot; or 5&quot; only.&nbsp; <br /> <br /> For these&nbsp;reasons I&nbsp;prefer the aluminum fence posts.&nbsp; It will be harder to cut, but much stronger and safer; well worth the extra initial effort.<br /> <br /> Good luck&nbsp;to all.&nbsp; I&nbsp;have run out of scraps due to popular response to my offer.<br /> <br /> -Keith R&nbsp; <a href="http://www.TrulyHomeGrown.com" rel="nofollow">www.TrulyHomeGrown.com</a>&nbsp;
Put the end of a length of PVC pipe into a vice, tighten it up, then heat with a torch. Continue tightening while heating, then turn. Keep going until you have somewhat of a square. I have done this before (not for this though). I am not sure what fumes or toxins are released while doing this so make sure you are in a ventilated area, also do at your own risk.
'<strong>When PVC is heated it releases clorine gas <em></em></strong><br/>
A chimney flue block (they are fired ceramic hollow squares with rounded corners) might work for a square blocker. I'm not sure if the come in 4" though.
I build a lot of fences, and of course end up&nbsp;with&nbsp;some scraps on hand.&nbsp; I made soil blockers from fence posts.&nbsp; Most residential aluminum fencing (like Jerith or Delgard) uses 2&quot;&nbsp;square posts.&nbsp; Perfect for the 2&quot;&nbsp;blocks.&nbsp; Square aluminum posts also come in 1-5/8&quot; , 2-1/2&quot;, 3&quot;&nbsp;and 4&quot;.&nbsp; It's light &amp;&nbsp;smooth and isn't PVC, for those concerned about chemical leaching.&nbsp;&nbsp;If you're not in the fence &amp;&nbsp;gardening business like I&nbsp;am, I&nbsp;bet you could ask nicely &amp;&nbsp;get permission to raid the dumpster of a fence company near you and get what you need.&nbsp; If you're in central NJ, I usually have some scraps I'd gladly give you for nothing.&nbsp; Contact me&nbsp;through TrulyHomeGrown.com<br />
Cool!&nbsp; That is a great idea.&nbsp; Thanks.&nbsp; I&nbsp;will look up your website. - Dave<br />
How about attaching these things to the drill-press? Would make pressing easier :<sup>)</sup><br/>
Ranie, No. It is just easy enough to pack the soil in by hand. It is a messy operation and you need to dunk in water after each one. This is really for the home hobbyist too where huge quantities are not needed.
Terrific instructible - Just what I was looking for. One suggestion, though. To make it easier to line up the 3/4" hole in the wood circles, first start the disk by using the smaller bit to just mark the center. Then you can use that to line up the 2" hole cutter bit and cut the circles with the center 3/4" hole already marked and started accurately.
Thanks for the input. Great idea!
This is great! Regarding the soil mix, I wouldn't use peat moss. It has anti-microbial properties (good organic soil is full of beneficial microbes) and a lot of energy is expended with harvesting and shipping it from Canada. There are some additional environmental negatives that I can't recall right now. Other than that, I'm definitely gonna give this a shot. Thanks!
Jason - You are right. You can substitute coconut coir which is a peat substitute and a completely renewable material. I have heard though that in order for a soil block to hold together, you cannot use it alone with the compost and perlite. It would have to be mixed 50-50 with the peat. thanks for your comment.
Hi Dave, Thanks for this. I needed to get off the couch. Jody
How many cups lime is that in step 6? All I see is a little question mark instead of 1/2 or 1/4 or 1/3 or whatever.
It is 1/2 cup. Sorry about that. I went back and fixed the text. Thanks for the feedback!
My mum & I just grow seadlings in small circular pot, plastic of course, then when time to put in the garden we just take the whole "block" out & bury it. Good work on the instructable, it's rather well set out & quite clear.
a fine and timely instructable! i'll soon be starting some vegetable seeds indoors for later transplant. Good Stuff, Dave!
This is a great idea. I think I will try this and replace my current method of using toilet paper rolls to hold the soil.

About This Instructable




More by DaveNJ:DIY Bike Repair StandMaking a Mini Soil BlockerMaking a Soil Blocker
Add instructable to: