In order to have soil that is optimized for growing fast, good quality veggies, the soil must have these characteristics:Sieving compost - I use a metal sieve which sits just inside the lip of a flexible bucket and makes it easy to remove any lumpy bits!

  • Drainage – The soil needs to have the ability to let water flow freely through it so the water does not stagnate and rot the roots. A raised bed garden will provide fantastic drainage.
  • Friability – A good soil will be light and fluffy, which contains air pockets. The pockets allow oxygen to get to the plants more readily and allows them to grow quickly. Ingredients that make your soil more friable  include:
    • Peat Moss
    • Coconut fiber (Coco Peat)
  • Water retention – this means that the soil can hold an optimum amount of water. This balance is important so that you don’t waste water or create a mix that actually repels water! Ingredients you can add to your soil to increase water retention are:
    • Vermiculite
    • Perlite
    • Pine BarkCoir peat brick - makes 9 litres
  • Nutrient retention – Good soil is designed to hold on to nutrients so there is less leaching which improves plant health and saves you money.
  • Plant Food – Essential nutrients for plant growth – the amount depends on how long you want the mix to feed your plants. Ingredients that will increase the nutrition of your soil include:
    • worm castings
    • bat guano
    • chicken manure
    • other types of compost
  • Support – The structure of the soil needs to be small yet strong so plants will be able to push their roots through it quickly.
  • Microbes – These little guys play a vital role in plant health and growth. Don’t be afraid of them – they will help give your garden long term health. Worms and other natural soil amendments will help keep your soil alive!

For a more in depth explanation, click below

A more detailed explanation


Coir peat brick - makes 9 litres

Here is an ideal way to get fantastic growth. This is a mixture you can adjust and see how it works for you – many gardeners have found it to be ideal for growing plants quickly.

1 part pre-soaked Coir Peat – Coir Peat is a cheap but long lasting renewable resource so it is a good environmental choice. Coir Peat is a waste by-product from the coconut-processing industry. The finer product left behind after the husk fiber is processed is called coconut coir or Coir Peat – not to be confused with peat moss!

1 part Vermiculite* (Grade 3 is a good size) – Vermiculite is the silvery grey color you often see in potting mixes. It is natural volcanic mineral that has been expanded with heat to increase its water holding capacity and can come from a variety of sources.

The flaky particles soak up moisture and nutrients and keep them in the mix so the plants can access them. It is lightweight and inorganic so is a permanent ingredient that will not deteriorate or lose volume in the mix. It is clean, odorless, non-toxic, sterile (no pathogens) and won’t become moldy or rot.

Vermiculite has a moderate CEC (cation exchange capacity) so can hold/make available minerals to the plants.  (* If unavailable, use coarse sand )

    • Vermiculite close upI prefer this medium to coarse washed river sand because it provides excellent drainage and has great moisture and mineral retaining properties whereas sand doesn’t. It also helps aerate plant roots, has good pore space and is a thermal insulator. Depending on which brand you buy, the pH may be a little alkaline.

2 parts sieved Compost – (preferably homemade but a commercial certified organic mix is an alternative if you don’t have your own).Compost retains minerals, provides moisture, plant food, and microbes, and improves the structure of the growing media. It also acts as a buffer to changes in pH and suppresses disease.

1/2 to 1 cup* Worm Castings or Vermicast (humus) – ideally you will have your own worm farm to add this perfect humus to your mix. Note: This is an approximate quantity based on making 36 liters (4 x 9 liter buckets) of potting mix using a 9 liter brick of coir peat. Feel free to add more if you have it! (If you can’t access vermicast, you can buy worm castings or use some humus from the bottom of your compost pile that is mostly decomposed or use good quality compost)

A 4 litre icecream tub is a good size container to use for measuring small quantities of mix.

Humus has so many benefits including the capacity to hold nutrients and supply them to your plants, incredible moisture retention capacity (holds 80-90% of its weight in water), prevents leaching, provides beneficial microbes, is a plant food source, a buffer for toxic metals and chemicals, and has the optimum soil crumb texture.

A “part” can be whatever quantity you need: a small scoop or ice cream tub, a 9 liter bucket or even a wheelbarrow depending on how much potting mix you require. I make 60 liters at a time in a large flexible bucket and store the rest until needed.

Thanks to the Micro Gardener for this great information!

Sieving compost - I use a metal sieve which sits just inside the lip of a flexible bucket and makes it easy to remove any lumpy bits!