SOIL BLOCKS

soilblocks.jpg

Every year we make up thousands of soil blocks . If there’s one tool a urban gardener/ farmers needs is this handy instrument. Not only does it help us with our successive planting efforts, soil blocks save time, space, money – seedlings germinate and grow with no container, NO transplant shock.

I just love sitting out in the warm sunshine, barefoot, with my hands squishing a bunch of moist soil into the soil blocks – plopping out these nicely shaped blocks all ready and waiting for the seedman (Justin) to come along.

WHAT IS A SOIL BLOCK?

A soil blocks is a block of growing medium that has been lightly compressed and shaped by a form. A soil block serves as both a container and the soil for starting and growing seedlings, eliminating the need for plastic pots and trays for transplanted seedlings. Seedlings grown in soil blocks form stronger root systems than those grown in containers due to increased oxygen to the roots and the soil block’s natural tendency to “prune” roots. This creates a substantial advantage when seedlings are transplanted into the field, because plants establish themselves more quickly and, because of lessened root disruption, they are less prone to transplant shock.

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.

BLOCKING MIX RECIPE *

A standard 10-quart bucket is the unit of measurement for the bulk ingredients. A standard cup measure is used for the supplementary ingredients. This recipe makes approximately 2 bushels of mix. Follow the steps in the order given.

3 buckets brown peat (standard peat moss, use a premium grade)
½ 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

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.

HOW TO USE THE SOIL BLOCK MAKER

Blockers can be used on any flat work surface. Push the prepared soil mix into a mound that is 1¼ to1½ times deeper than the height of the soil blocker. Push the blocker into the mix until it strikes the work surface. Twist the blocker a quarter-turn and lift. Set the blocker where you plan to grow your seedlings such as a wooden or plastic tray, push down on the handle while raising the blocker. Rinse the blocker in warm water before making the next set of blocks. Place the seed into the indentation of each block, and cover according to the culture information on your seed packet. Prevent drying by covering blocks with a plastic dome or a layer of plastic until the seeds have germinated.

Courtesy Johnny’s Seeds

:: Resources ::

YouTube Video of urban farmer Justin using soil blocks to plant tomatoes

Soil Block Maker

Comments(28)

  1. Claudia Griffith says:

    This Soil Block post was so helpful! I have always wondered how these worked and what were the benefits. Now I will try them.
    Thanks
    CG

  2. Brandi says:

    I bet kids, like my own, would also love making these blocks, Anais!

    This is a really lovely idea, but I wonder if there’s anything besides peat that can be used as fibrous material? Coconut hull fiber? Grass clippings? Aged straw? Leaf mould? I hate using peat because of the rapidly depleting bogs…

  3. Anais says:

    Hello Claudia

    Thanks for the comments, glad you enjoyed the post. I can’t say enough positive things about soil blocks. They really make for successful growing here on the urban homestead.

    Anais

  4. Anais says:

    Hi Brandi,

    Kids would love it…. I do!

    As for peat moss. There are indeed alternatives.

    Sphagnum peat moss is NOT a threatened resource

    See these these sites for information:

    Canadian Sphagnum Peat Moss and the Environment
    http://www.peatmoss.com/concern.html

    Peat Moss and the Environment — FAQ
    http://www.peatmoss.com/pm-efaq.html

    Peat Moss
    http://journeytoforever.org/compost_peatmoss.html

    Here’s another helpful article:

    Alternatives to using peat moss in the garden
    http://www.essortment.com/all/peatmoss_rtfv.htm

    Hope this has helped answer your questions.

    Cheers,
    Anais

    • Beverly says:

      @Anais, OK, I know I’m writing 3 years after this was posted, but it prompted a google search on peat moss since I know nothing about it. This article seemed balanced and interesting: http://www.naturallifemagazine.com/0712/asknlpeat.html

      Sounds like using spagnum peat is not the worst thing you could do (we are still growing our own organic food, after all) but still worth thinking about.
      Question: If I’m just starting out with the soil blocks, do you think I could make them by hand? I’d love to buy a blocker some day but it’s just not in the budget at the moment.

  5. Brandi says:

    Thanks for the links, Anais. I’m checking them out now.

  6. Donella Lyonesse says:

    How do you go about making soil blocks, the frames that is, I read this through twice and see no mention of it. I use a square foot garden method of planting and love this idea as I could have the next plants starting while I am finishing up the first crop.
    Very informative information

  7. Anais says:

    Greetings Donella

    We make up soil blocks using this nifty piece of equipment

    http://www.peddlerswagon.com/p-107-soil-block-maker-4-blocks.aspx

    Glad you enjoyed the post!

    Anais

  8. AND THEY’RE UP! | Little Homestead in the City says:

    […] a previous entries on making an using soil blocks for your reading […]

  9. Lily says:

    Thanks so much for this post, I’d seen the block maker on Peddler’s Wagon, but I was having trouble visualizing the process and result. That blurb from Johnny’s Seeds is very informative, however, I am wondering what mix you guys use. The list from Johnny’s appears to contain quite a few purchased ingredients which would be a less than ideal recipe if you are trying to maximize self-sufficiency.

  10. gardener’s little helper « Not Dabbling In Normal says:

    […] my second year for using soil blocks. i finally mixed all the ingredients for the soil block maker recipe as recommended by eliot coleman and used by the fine people at path to freedom (where i purchased […]

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  12. namgya wangdi says:

    thank you very much 4 your site. i am from the himalayan region of Nepal, my village is at 3800 meter height and there’s houses are mostly made from soil, i want make house there with modern technology, with means soil block. so what is the better and easy way to make soil block?

    • Sarah says:

      @namgya wangdi,

      I believe this is more like what you might be interested in:
      http://en.wikipedia.org/wiki/Super_Adobe
      If you look up “superadobe” or “superblock” or the architect Nader Khalili, you should find relevant information. University-based architecture programs might also be doing research into efficient use of native materials in building. Good luck!

  13. Gardening « The Next Thing says:

    […] seeds used, chemicals used, etc. I make soil blocks they have a recipe on this site but here is a link to what I’ve been using. You can make the mix and use the little trays instead. I am trying […]

  14. DISPATCHES FROM THE URBAN HOMSTEAD pt 3 | Little Homestead in the City says:

    […] reminds me, gotta get on the stick and start whipping out more soil blocks — and […]

  15. Levi Gardner says:

    Hi – this is my first year using blocks and eliot coleman’s recipe. i got most of the blocks started in the past week and they are germinating well – but this weird fuzzy static is coating the outside of some of the blocks. It seems to be some form of lines of condensation; but I’m also worried that maybe i’m not watering enough. I built the trays as recommended in Coleman’s book so I can’t bottom water – do you have any suggestions? Any help would be wonderful.

    Also – if not bottom watering, approximatley how much water do 2″ blocks need per week?

    thanks.

  16. SUMMER SOIL BLOCKING | Little Homestead in the City says:

    […] An ideal soil mixture must be fibrous enough to hold together through many waterings – Basic Soil Mix Recipe ( you can definitely modify) […]

  17. Successful Garden Tip: Soil Blocks | Freedom Gardens says:

    […] An ideal soil mixture must be fibrous enough to hold together through many waterings – Basic Soil Mix Recipe ( you can definitely modify) […]

  18. Germaine Jenkins says:

    Got the materials and hope to make the soil blocks tomorrow for direct planting into a new bed, in grow bags and in the winter sowing of fruits and veggies for the spring. Thanks as always for the inspiration!

    • Anais says:

      @Germaine Jenkins: Happy soil blocking!

  19. Soil Blocking on the Cheap | Freedom Gardens says:

    […] my 15 year old daughter.   I used the Eliot Coleman recipe (from The New Organic Grower) that Anais provided to make the blocking mix with a couple modifications.  *For convenience, the complete block mix […]

  20. Richard says:

    I used a soil blocker last year. I planted very early and got a good number of seeds to sprout by March 1, using a small greenhouse and electric heating pads to protect early.
    My growth was terrible in the garden. Halfway through the growing season, I began to notice that the blocks had turned into a cement-like composition that was killing binding the roots quite badly.
    I’ll try again, using the assumption that I had too much sand in the mixture.
    Any thoughts?

  21. Amy @ Homestead Revival says:

    I just received my two soil blockers and looking forward to using them. Thanks for the recipe. I’m going to give it a try just as soon as I can gather up the ingredients. You’re tips should prove to be very helpful!

  22. Glencliff Garden » Blog Archive » 2009-2010 Trials and Tribulations of Urban Community Gardening at Glencliff High School says:

    […] soil block method was developed by Elliot Coleman, an organic farmer in Maine.  Through trial and error, he created […]

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  24. Raviteja says:

    Hi Lark, Thanks for your encouragement. Yes, those pine trees could be quite pcrkily! Will cut the odd looking one and trim up the other two. Cost-wise it is very comparable, but mostly it’s more strategic to move bags rather than wheel-barrowing and dumping in the areas we have available for planting.

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