DIY Soil blocks
It’s seed sowing time and we thought we’d try something besides the typical seed-starting trays, newspaper pots or cow pots. Soil blocks are, essentially, compressed planting mix that do not require a vessel in which to sit. Commercially available soil blockers are great, but they’re pricey for a small-scale gardener. With soil blocks, once the seed has germinated and a root system has been established, you simply make a larger soil block with a divot that matches the smaller block and “pot up”. Potting up eliminates much of the shock a plant experiences when it’s transplanted.
Our point here is not to come up with the ultimate soil block maker, but to show that DIY means figuring out what works for you without needing to buy a fancy gadget. So, after digging around in the recycling bin, we tried making soil blocks using takeout containers and a ballpoint pen. Seems all of our photos have disappeared, and are nowhere to be found – dang!
Keep in mind that these round blocks can dry out very quickly, so it’s important to mist them daily and bottom water them regularly. The advantage of square soil blocks is that you can align them squarely (duh) and maintain the moisture content a bit better. So, we tried again using an ice cube tray and food storage containers. The ice cube tray worked well for a one-seed mini soil block and the larger container for “potting up”.
Do you have any thoughts? Are our designs offensive to logic and common sense? Do you have any ideas for DIY gardening tools? Let us know!
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Tags: DIY, seeds, soil blocks, sowing, transplanting
February 17th, 2010 at 9:12 am
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February 18th, 2010 at 9:17 am
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February 19th, 2010 at 11:53 am
An update: Exactly one week later, I have sproutlings! The round soil blocks have actually stayed moist (with bottom watering) and – evidently – the seeds like it! Whoo hoo for DIY experimentation!
March 22nd, 2010 at 5:25 pm
I have been pondering for some time now on how to make a soilblockmaker that makes 6 or more square blocks in one turn.
Does anyone have an idea?
Best wishes,
Heidi from the Netherlands
February 18th, 2011 at 1:06 pm
Home Made soil Block Maker. There are several ways.
1/ Use 2×2 (50cmx50cm) square aluminum tube purchased from the Hardware department, this tube is also used for wrought iron fence panels. Cut 2.5 (75 cm long) 4 or 6. Now glue these together using Gorilla Clue (Poly urethane) glue, this foams up when in contact with damp surfaces. This will glue metal together with excellent results. Then you will need a plunger for each section to eject the soil block. The trick is to have all these plungers fixed and level, so when ejected all ejects at the same time.
2/ Fill all the tubes with soil, compress the soil, fill some more, then place the ejectors on the soil compress. and the slide the tubes up the ejectors. There you will have soil blocks. Other refinements were made, but too hard to describe in words.
February 23rd, 2011 at 3:11 pm
Thank you sooooo very much! I’d have never thought of this. Truly a huge money saver 🙂
March 15th, 2011 at 11:14 pm
The key to making good soil blocks is to use a mix containing the correct proportions of peat, compost, soil, and sand or perlite. A “blocking” mix needs extra fibrous material—peat—to bind the material together and help the block retain moisture. Some commercially available peat-lite mixes may work but often contain wetting agents and/or fertilizers that make it unsuitable for organic use.
This is the mixture provided in “The New Organic Grower” by Eliot Coleman. This is assuming you use 5 gallon buckets and makes 4 bushels of soilless mix, so you may need to scale it down a bit:
3 buckets brown peat (standard peat moss, use a premium grade)
1 cup lime. Mix ingredients together thoroughly.
2 buckets coarse sand or perlite
6 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.
Moisten the mix thoroughly using one part warm water for every three parts blocking mix. Successful soil block making depends on the mix being wet enough, rather than wet like soil mix in traditional flats. The mix should have the consistency of soft putty or wet cement, so that a small amount of
water oozes through small openings in the blocker as the blocks are made, and that the individual soil blocks cling to the blocker without falling out prematurely.
March 16th, 2011 at 11:39 am
I liked the concept of your idea. I found one of the metal soil block makers at a thrift store so for $2 have been able to make mine. I am however interested in what you have here. I wonder about the affect of the sloping sides of your blocks and if it might have some consequences. Just a thought. Otherwise I say “Bravo” ! Like it enough I’ll be sharing your idea with my garden peeps at a meeting on sustainable food in our city this evening.
February 8th, 2012 at 11:21 pm
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October 31st, 2012 at 1:24 pm
Hi. Just found this site, good info, well done.
My father has a farm and we have access to hundreds of tons of farm yard manure from cows bedded on straw.
Non of it has been composted but some is a year old with little sign of the straw left. I assumed that it would be ideal for making blocks but most sites seem to advise against it but they just say it would be smelly, which would not be a problem for me ! 🙂
Are there any other disadvantages to using it ? I intended to add sand or perlite to it, is there anything else that could be added ? Cheers
November 22nd, 2012 at 2:41 pm
Thanks for the great ideas on DIY soil blocks!
Also, to Allan: I’d be concerned about the manure burning the roots of the plants unless it’s been thoroughly composted. It also shouldn’t smell like dung *if* it’s been thoroughly “cooked”–good luck!
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