So you want to make your own seed-starting mixes and potting soils, eh?

These are my personal recipes which have given me good success. Feel free to expand on these or modify them for your needs.

soil mix homemade soil blocking coco coir compost sand
Compost, coco coir, and some sand (or perlite) makes for a great seed-starting mix


Some important notes before you jump in:

  • Coco peat and peat moss can be used interchangeably. Peat moss is cheaper, coco peat is likely more environmentally-friendly.
  • Recipes are all listed as ratios (2 parts x, 3 parts y) to allow for easy scaling.
  • Parts are measured by volume, not by weight.

Basic Seed-Starting Mix

perlite coarse in hand white rock for planting mixes drainage
Perlite is one of the main ingredients you'll need for most custom soil mixes.

Soil Blocking Mixes

These are the mixes which I use with the Ladbrooke soil blockers. If you're not familiar with them I highly recommend checking them out when you're ready to step up your seed-starting game.

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I use the native sand from the desert where I live for drainage, while typically perlite would be used for this purpose. If you don't have abundant free sand, perlite is likely a better option for you

soil blocking mix homemade dirt compost sand coco peat
The compost, coco coir, and desert sand from the first photo, mixed together as a soil blocking mix

I find the native sand where I live contains just enough clay to help bind my soil blocks together, while also introducing indiginous microorganisms (IMO) to my seedlings and preparing them for encountering the highly alkaline native soil once they're transplanted out.

If you don't live in a desert where sand and sun are abundant, consider what resources your region does have in abundance and leverage them where you can. Perhaps you've got rich native soils you can incorporate into your blocking mixes, for instance.

3/4" Micro Blocks

  • 4 parts coco peat
  • 1 part screened cured compost
  • small scoop of native desert sand
tray of seedlings soil blocking micro blocks
The same soil-blocking mix from above, stamped into 3/4" soil blocks

2" Mini Blocks

  • 3 parts coco peat
  • 2 parts screened cured compost
  • small scoop of native desert sand
trays of soil blocks 2 inch mini blocks transplant dibbles
2" soil blocks with dibbles that fit the 3/4" blocks perfectly when it's time to transplant

4" Blocks

  • 2 parts coco peat
  • 1 part compost
  • small scoop of native desert sand


The 4" blocker does not come with the essential kit from Ladbrooke, but is available separately here. There is also a master grower kit which includes all 3 sizes together.

Potting Mixes

House Plant Mix

Succulent Mix