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Seed Starting Soil Mix

This soil mix is specifically made for starting seeds using the method described in Eliot Coleman's book The New Organic Grower.

Since we were selling to the public previously, we used large quantities of this mix and therefore mixed it in quantities that aren't necessarily going to work for a small family garden.

Below we'll show your the mix as we make it and below that you'll find options for various ingredients and a mix that is a bit smaller for the backyard garden.

To see this in action, see our video here.

A standard 10-quart bucket is the unit of measurement for the bulk ingredients.  A standard cup measure is used for the supplementary ingredients.


The following recipe makes approximately 2 bushels of mix.  


  • 3 buckets brown peat moss (standard peat moss, easily found at most big box hardware stores such as Lowes.

  • 1/2 cup lime.  Garden lime is a rock powder that "sweetens" a soil - that is it can make a "sour" soil more alkaline.

**Mix these two ingredients together first.  The peat moss is acidic so mixing in the garden lime helps to sweeten it before you add the additional ingredients.​

  • 2 buckets coarse sand or perlite (either can be found at Lowes or similar)

  • 3 cups fertilizer.

**We make our own fertilizer using a mix of equal parts blood meal and greensand.  You may also want to add equal amounts of colloidal phosphate.  We have high phosphate in our soil so we leave this out.​

**Another option if you can't find greensand for this portion of the mix, is to simply purchase a bagged fertilizer such as Gaia Green 4-4-4.  This can be found here.

Or check at your local garden store for a similar organic fertilizer.

  • 1 bucket garden soil.

  • 2 buckets well-decomposed compost.

**If you do not have your own compost, a good alternative is available at garden stores.  One we like is a mushroom compost which we find at Lowes.​

Mix all of these ingredients thoroughly

Moisten the mix well using 1 part warm water for every 3 parts blocking mix.  Successful soil block making (if you are using a soil blocker) depends on the mix being wet enough.  The mix should have the consistency of soft putty or wet cement, so that a small amount of water oozes through the small openings in the blocker as the blocks are made.


  • 1 gallon brown peat moss

  • 1/8 cup of lime

**MIX WELL** ​

  • 3/4 gallon coarse sand or perlite

  • 1 cup fertilizer

  • 1/3 gallon garden soil

  • 3/4 gallon compost

  • Water, enough to make a "wet cement" feel for the soil blocks to be made.

If you do not have a soil blocker, you can use this in any medium you wish and you will still obtain good results for starting your seeds.

To order a soil blocker, go to the Johnny's Seed website where you'll find a nice selection to choose from.

Happy Planting!

Tiny Green Plants
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