Chapter 67 Other Specialty Container Mixes

I have come across several soil mix protocols while looking for other things. Most of the ones I have outlined below are designed for general nursery production, not bonsai trees, but they may be useful for growing accent plants, vegetables, or other plants you have around.

67.1 Cornell Soilless Mix

This soilless mix was developed at Cornell University for commercial organic growers. It replaces synthetic fertilizers with organic alternatives.

  • 1/2 cubic yard peat moss or coconut coir
  • 1/2 cubic yard perlite
  • 10 lbs. bone meal
  • 5 lbs. ground limestone
  • 5 lbs. blood meal

67.2 Woody Plants and Perennials

This long-lasting mixture is the perfect medium for long-term plants.

  • 1 part peat moss
  • 1 part composted bark
  • 1 part compost
  • 1 part sand
  • 1 part perlite

If the mix clumps together and the compost you use is heavy, add more perlite to ensure good drainage. Use extra compost or bark when growing more mature plants, but don’t make it too rich for young plants—it could damage their delicate roots and stems.

67.3 Annuals Mix

High in nutrients, this mix pumps out the flowers without extra feeding.

  • 1 part expanded slate
  • 1 part composted chicken manure
  • 1 part worm castings
  • 1 part composted pine bark
  • 1 part coarse river sand

The worm castings and chicken manure provide enough nutrients to last throughout the season and the pine bark continues to increase fertility as it decomposes, so this mix requires little or no extra feeding on your part.

67.4 Alpine Plants

A low fertility mix.

  • 1 part expanded slate or shale
  • 1 part bagged potting soil
  • 1 part bagged playground sand

Alpine plants are adapted to survive in the bare minimum of soil conditions, so many store-bought mixes high in organic matter won’t work. This recipe makes a lean soil that alpine plants love, but make sure the potting soil you use has no added synthetic fertilizer.

Mulch the surface of the soil with small pebbles or grit to keep the crowns of the plants from rotting.

67.5 Tropicals

Though tropicals are a diverse group of plants, they generally prefer a loose, acidic, well-drained, fertile soil high in organic matter. Common tropical plants, like cannas and bananas, will grow in any good soil, but this mix will help them attain optimal growth.

First, mix together:

  • 2 parts composted bark
  • 2 parts pure pine bark
  • 1 part rice hulls
  • A handful of charcoal pellets

Then combine:

  • 3 parts above mixture
  • 1 part peat moss
  • 1 part perlite
  • 1 part calcined clay (Turface or other baked clay particles)

67.6 Succulents

Perfect drainage makes this recipe succeed.

  • 5 parts perlite
  • 4 parts bagged potting soil
  • 1 part coarse sand
  • Pinch of rock dust

Top-dress the container soil with small river rock, gravel, aquarium stone, or a fine-grade roofing gravel to keep the crowns of the plants from rotting.

To increase acidity just slightly—something all succulents like—add 1 tablespoon white vinegar to 5 gallons water when watering.

67.7 Succulents Mix #2

  • 2 parts black topsoil
  • 1 part peat moss
  • 1 part perlite
  • 1 part coarse sand

67.8 Foliage Plants

  • 2 parts peat
  • 1 part perlite
  • 1 part coarse sand

67.9 Bromeliads

  • 1 part peat
  • 1 part bark
  • 1 part coarse sand

67.10 Seedlings

  • 2 parts compost
  • 2 parts peat moss
  • 1 part vermiculite (pre-wet)

67.11 Blocking Mix

This mixture is for use to make soil blocks for seedling/transplant growing. Mix all together thoroughly. Ingredients can be measured with a standard 10-quart bucket. You will need a block mold for stamping the blocks; check out Johnnys Seeds for options.

  • 30 quarts brown peat
  • 20 quarts sand or perlite
  • 20 quarts compost
  • 10 quarts black topsoil
  • 3 cups base fertilizer (equal parts blood meal (N), colloidal phosphate (P), greensand (K))
  • 1/2 cup lime

67.12 Basic Container Mix

  • 1 bucket (2.5 gallons) peat moss
  • 1 bucket(2.5 gallons) vermiculite or perlite
  • A half bucket (1.25 gallons) screened compost or composted cow manure
  • 2 cups fine sand
  • 2 cups pelleted time-release fertilizer
  • 1/2 cup lime (to counter the acid of peat and keep the pH level near neutral)

67.13 Classic/Basic Soil-Based Mix

  • 1 part peat moss or mature compost
  • 1 part clean builder’s sand or perlite
  • 1 part compost
  • 1 part garden loam or topsoil
  • Optional: a handful each of:
    • Garden lime
    • Soybean meal
    • Rock phosphate
    • Kelp meal

Moisten the ingredients to make mixing easier. Place a 1/2 inch mesh screen over a garden cart or other large container, and sift all ingredients to remove any large particles. Mix thoroughly.

The handfuls of garden lime, soybean meal, rock phosphate, and kelp meal (any of which can be omitted) provide extra nutrients that enable this mix to feed plants for a year or two without additional fertilization.

67.14 Peat-Lite Mix A

This recipe makes one cubic yard of media

  • 0.5 cubic yard shredded peat moss
  • 0.5 cubic yard vermiculite (#2 or 4)
  • 5 lb. finely ground limestone
  • 1 - 2 lb. powdered single superphosphate
  • 1 lb calcium nitrate (453g)
  • 3 oz. fritted trace elements (84g)
  • 2 oz. iron sequestrene 330 (56g)
  • 3 oz. wetting agent (84g)