Potting Mix I


Greetings, readers!

We have come full circle in our blog posts and are now back to the category of KnowYourEssentials. For these two weeks, we look at the most basic medium that you need to be familiar with for any kind of gardening- potting mix. It is important to familiarize yourself with the different components/ingredients and their respective functions in order to know the best potting mix that you need for the plants that you intend to grow.

Components of Potting Mix

Ideally, a general potting mix should be able to retain moisture, is light and airy, contains nutritional value for the plant and does not break down or become compacted easily.

 As a more detailed guideline, components of your potting mix should provide:
  • Drainage– to help hold the soil structure open so water moves through and it doesn’t become anaerobic.
  • Aeration– a good mix will be light and fluffy, allowing air pockets to form in the soil structure so your plant roots and micro organisms have the oxygen they need to thrive.
  • Water retention– moisture-holding capacity is essential or you will have a water repellent mix and waste money on unnecessary watering.
  • Nutrient retention– ingredients that bind or hold onto the minerals means less leaching of nutrients; improves plant health and saves you money.
  • Plant Food– vital nutrients for plant growth – the amount depends on how long you want the mix to feed your plants for.
  • Support – the soil crumbs need to be small and fine so the plant roots (especially young seedlings) can take hold and easily expand through the mix.
  • Microbes– play a vital role in plant health and growth and I include them in my mix although many mixes are devoid of soil life.


Some of the common components used in potting mix include coco peat (also known as coir peat), vermiculite, perlite, compost, worm castings/vermicast, and other nutrients and slow release organic fertilizers. In addition to these components, the Premium Planting Mix that we use ourselves here at Nóng and Edible Gardens also contains humic acid, photogenic agents, buffering agents and anti-fungal agents.

In this first of our two posts on potting mix, we will cover three of the more common components: coco peat, vermiculite and perlite.

Coco Peat (Coir Peat)








Coco peat is a multi-purpose growing medium made out of coconut husk that is excellent for hydroponics, soil mixes, and container plant growing. Fibrous coconut husk is pre-washed, machine-dried and then sieved. The final coco peat product is free from sand, soil-borne pathogens and weed, as well as other contaminations such as animal and plant residue. Coco peat is a very good alternative to traditional peat moss and it is 100% organic and eco-friendly.

This clean coir product has:

  • Natural rooting hormones and anti-fungal/anti-bacterial properties.
  • Air-filled porosity and high water-holding capacity, which makes it an ideal growing medium for plant crops. Coco peat holds water rather than shedding it like peatmoss does and it can hold up to 8-9 times its weight in water.
  • Ability to store and release nutrient to plants for extended periods of time. It also has great oxygenation properties that are important for healthy root development.
  • Has a pH of 5.0-6.8, which is neutral to slightly acidic. This makes it great for alkaline garden soils.

 Moreover, coco peat also  

  • Is very slow to disintegrate. While peat moss breaks down within two years after application, coco peat only begins to break down when it is 10 years old.
  • Can be reused for up to 4 years!
  • Makes a great bedding material for worm bins and increases worm growth by 25%.


Vermiculite is the silvery grey colour 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 it is a permanent ingredient that will not deteriorate or lose volume in the mix, clean, odourless, non-toxic, sterile (no pathogens) and won’t become mouldy or rot.
  • It also helps aerate plant roots, has good pore space and is a thermal insulator.


Appearing as tiny, roundish white specks amid the other components, perlite in potting soil is a non-organic additive used to aerate the media. Perlite is a volcanic glass that is heated to 871°C whereupon it pops like popcorn and expands to 13 times its former size, resulting in an incredibly lightweight material.


The super heated perlite comprises of tiny air compartments. Under a microscope, perlite is revealed as being covered with many tiny cells that absorb moisture on the exterior of the particle, not inside, which makes it particularly useful in facilitating moisture to plant roots. Perlite is used in soil mixes to improve aeration and modify the soil substructure, keeping it loose and well draining. Perlite is also great for rooting cuttings and fosters much stronger root formation than those grown in water alone.


That’s all for this week, folks. STAY TUNED to next week’s post! In the meantime, have a happy weekend and remember to wear a mask if you need to go outside :)

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