soilless mixes

(Part 1) Peat Moss vs Coconut Coir: 6 Ingredients for Easy Soilless Mixes

The 6 Ingredients of a Soilless Mix, Part 1: Peat Moss vs. Coconut Coir

Most soil mixes for a container plant contain little to no soil at all, which is why they are called soilless mixtures. They are usually comprised of a combination of organic matter, like peat moss, and inorganic material, like perlite or vermiculite. Indoor plants can thrive in actual soil from your backyard – just make sure you know what your plant needs and what type of soil you have!

Many of the ingredients for these soil mixes can be confusing for a first time DIY-er, so I’ve compiled a short list of the main components and how they differ. For this first installment, I compare the advantages and disadvantages of peat moss and coconut coir so you can decide which is best for you and your plants.

soilless mix
ingredients for a soilless mix

Peat Moss vs. Coconut Coir

Sphagnum peat moss – commonly known as peat moss – and coconut coir – the fiber from the coconut husk – can both be used as soil amendments for your yard. They are usually the base of the soilless mix, depending on your plant’s needs. Peat moss is harvested from swamps or marshes, whereas coconut fiber is a byproduct of coconut processing.

Although peat moss is extremely popular, peat bogs take at least 25 years to renew and some wetland ecologists claim that peatlands are being harvested at non-sustainable rates. However, industry officials in Canada – North America’s main source – have implemented measures to ensure that the harvesting process is more responsible and sustainable. Nevertheless, wetland ecologists, industry officials, and horticulturists agree that coconut coir is a suitable alternative, especially since the leftover fibers would be thrown out as waste into landfills.

Though incredibly similar, these “soils” have subtle differences that will determine what plants will thrive in which soilless mix.

(Sphagnum) Peat Moss
  • After being processed, peat moss is light brown, fluffy, and soil-like
  • Has a pH level ranging from 3.3 to 4.0 (very acidic)
    • Plants such as blueberries and camellias love – and thrive in! – the acidity
    • However, it has the potential to harm plants that are less tolerant to low pH levels
      • Lix’s Pro Tip: add limestone to raise the pH level!
  • Holds an average of 10 to 20 times its dry weight in water
  • Advantages
    • Optimal for starting seeds because of its water retaining capabilities
    • Great aeration, which allows roots to breathe, grow, and better absorb nutrients
    • Easy to find
  • Disadvantages
    • Peat moss can contain bacterial and fungal spores that can contaminate plants
    • Has no nutrients – make sure you feed your plants accordingly!
    • When dried out, becomes hydrophobic (literally means “fear of water” – so the “soil” will not absorb any water)
      • Once this happens, it is nearly impossible to rehydrate
Coconut Coir
  • After being processed, coconut coir looks similar to peat moss, though it can vary in color
    • Often comes in dense, compressed blocks that are expanded by soaking in water
      • Depending on the quality and manufacturer, processed coir can have varying levels of stringy fibers
  • Has a pH level ranging from 5.2 to 6.8
  • Holds an average of 8 to 9 times its dry weight in water
    • However, needs less water than peat moss, since it requires less time to become saturated
  • Advantages
    • Coconut coir is reusable for approximately 5 years with proper conditioning – just make sure you break up, rewash in distilled water, and dry out the coir between uses!
    • Great aeration, which allows roots to breathe, grow, and better absorb nutrients
  • Disadvantages
    • Has little nutrients – make sure you feed your plants accordingly!
    • Depending on the quality, it may have high levels of salt content; however, this may be fixed by thoroughly washing and soaking the fibers in distilled water
    • Difficult to find in bulk

Images of Peat Moss and Coconut Coir

Leave a Reply

Your email address will not be published. Required fields are marked *