Soil 101


General Tips for buying soil

  • Ask around from sources that you trust
  • Don`t buy brand name pellets and compressed pots
  • Lift the bag – shouldn`t be too heavy or too light
  • Don`t buy Miracle Gro!

The Prob with Peat.

Peat moss has two settings: too wet and too dry. It grows algae, it attracts fungus gnats. It is also unsustainable – Coconut coir – It is the waste product from coconut’s outer husk. Coir holds just the right amount of moisture, and when it does dry out, it remains hydrophilic (receptive to water). It is less dusty than peat, seems to hold more air, smells good, and doesn’t break down as fast. Finally, it is a good use of a “waste” product.

Look at the ingredients listed on the bag: A good potting mix will contain organic matter such as compost, seaweed, manure or mushroom compost, bat guano, bone meal, soybean meal, soft rock phosphate, greensand, fish meal, blood meal,and/or worm castings (to name a few) to provide nutrients. Some mixes contain slow-release, chemical fertilizer pellets that are not considered organic. Perlite, vermiculite, wood chips, rice hulls, turface, chicken (or other) grit, and/or sand is added to prevent compaction and increase drainage. Peat or coir (a renewable resource and peat substitute derived from coconut husks) are two common ingredients used to to absorb water.

Basic Seed-Starting Mix

1 part sifted coir or peat

1 part perlite (best if you can find a fine grade)

1/2 part vermiculite (I used to use 1 part but have started using less).

You can add a bit of sifted and sterilized compost, or vermicompost to this (no more than 20%) or wait until the seedlings have produced their first set of true leaves and start to scratch a small amount at a time into the soil surface. I have started experimenting with mycorrhizae added to my mix, but can’t report on that yet.

Basic Potting Soil

2 parts coir or peat

2 parts sieved compost

1 part course sand (builder’s. Make sure it is free of herbicides), grit, and/or perlite

1 part vermiculite (optional, but I like it for water absorption)

You may need to add nutrition based on the type of plant you intend to grow in the pot. I do not add it to the basic mix so that it can be amended further (with more grit) to make potting soil for herbs, cacti, and succulent plants that do not require as much soil nutrition.


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