What is Peat Moss and How to Use Sphagnum Moss In Gardening

Peat Moss – a timeless favorite for farmers and gardeners alike.

Now you probably wondering what is it? how it’s different than sphagnum moss.

In this post, I’m going to help you to find out everything you ever wanted to know about plus how to use peat moss in your hydroponic or soil garden!

Any gardener knows that the secret to gardening success is your growing medium.

Whether you are a conventional gardener or a hydroponic grower, the soil or growing medium needs to provide the plant root systems with;

  • Good aeration
  • Good drainage
  • Enough moisture
  • And the ability to absorb nutrients.

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What Is Peat Moss And Where Does It Come From?

Peat moss is probably a word you have heard before, but do you actually know what it is and the role it plays in determining the quality of a good compost?

Quite honestly, the first time I used it I thought it was awful stuff.

I didn’t know you had to actually soak it first and then use your hands to mulch it up and squeeze out the moisture before you got the lovely spongy, workable end product.

Now I can’t live without it!

Traditionally, peat moss has always played a vital role in improving the soil.

It is a major component in the growing mediums formulated for seedlings, right up to the compost used for transplanting trees and shrubs.

It has many practical applications and benefits as well as a few drawbacks.

Difference Between Sphagnum Moss And Peat Moss?

Common green peat moss

Peat moss is also known as Sphagnum peat moss.

The difference is simple. Peat moss is just dead Sphagnum moss.

This primitive plant species known as Sphagnum moss is part of the group of plants known as Bryophytes.

These plants bear no seeds or flowers, producing spores instead.

They thrive in moist, shady environments, and when the mosses decompose these wetlands turn into peat bogs.  

Wet, cold, oxygen-poor conditions mean that the presence of bacteria is reduced and plant growth is greater than the rate of decomposition.

Over time the dead vegetation turns into peat moss.

Both the living sphagnum and the dead peat mosses are harvested.

First, the living moss is harvested, and then the dead.

Sphagnum moss is used differently from sphagnum peat moss as they are very different in appearance and function.

Sphagnum moss is the top of the bog and peat moss is the decomposed product deeper down.

Different grades of peat moss are graded using the Von Post Scale for Decomposition, where H2 is the light, spongy formation also known as blonde, and H8 is the dark, decomposed, peat that feels like putty.

The scale starts at H1 and goes up to H10.

The largest peat bogs are found in Russia with Canada coming in second.

Countries like Finland, Sweden, Ireland, and Germany also have ideal climatic conditions for bogs to develop.

Why Use Peat Moss in Your Garden

Peat moss is first and foremost a soil conditioner.

Soil conditioners repair damaged soil by loosening compacted soil to improve aeration, increasing the water holding capacity.

By helping to bond nutrients and water together to help the roots absorb both moisture and food.

The greatest demand for peat moss (source) comes from the horticultural industry but it is used by farmers, landscapers, and gardeners alike. It also has important uses in other industries.

Not only is it a porous, fibrous material, it also bears traces of vitamins, polyphenols, and humic acid.

It has a slightly acid pH and an above-average moisture-holding capacity.

But the nutrients in it are by no means sufficient enough to call peat moss a fertilizer.

It is however a disease suppressant (source) and free of weed seeds.

As a soil conditioner and amendment to growing mediums it has many benefits:

Pros and Cons on Using peat moss in your Garden

Advantage of Using Peat Moss

my organic garden

Peat moss pH is slightly acidic

This increases the soil’s buffering capacity, preventing the leaching of fertilizer nutrients. It also means it is ideal for a wide range of acid-loving plants.

Loosens Hard Compacted Clay soils

Peat moss loosens hard compacted soils, improving their porosity, while still keeping its absorbency. Due to the slow decomposition rate, one application can last a long time.

Retains water well

Peat moss increases the moisture-holding capacity in sandy soils, conditioning, increasing absorption rate, and raising the bioavailability of nutrients.

Used as a soil amendment

Peat moss can be used as a soil amendment and can be added to compost and potting mixes. Because it acts as a soil conditioner, it is an important additive to any custom compost or potting mix.

A compost/potting soil with peat moss will have a longer lifespan than one just using plain bark chips, for example

Pro tip: On its own peat moss is just crumbly or powdery dry matter but once soaked and allowed to absorb water it becomes a spongy, workable medium.

So make sure to pre-soak before adding to your mix. Pre-mixed composts or other growing mediums already containing peat moss will eventually rehydrate.

Sterile growing medium

Peat moss is weed and pathogen-free.

It has disease suppressing qualities against certain root-rot pathogens.

Peat moss is ideal as a component in hydroponic growing mediums or as a soil amendment to growing mixes like potting soil.

Peat moss is organic

Used for propagating seedlings both in organic farming and hydroponics.

Pro tip: To make sure you buy peat moss suited to your specific needs, check to see if it is pure and organic or if it has been supplemented with other ingredients or fertilizer, which could kill sensitive carnivorous plants.

Increases nutrients in the soil

Known as cation exchange capacity (CEC), this means nutrients in the soil are unlocked and become available to plant through the roots.

Slows down decomposition in Compost

What makes peat moss unique? is that it has a slower rate of decomposition due to its ability to decompose without oxygen (anaerobic).

It won’t rot in wet conditions making it great for adding to compost heaps where you want to lock nutrients in and slow down decomposition.

Peat Moss is Readily available

All these characteristics aid and improve nutrient absorption which in turn helps a plant to grow strong and healthy and produce good quality flowers and fruit.

In today’s world where our soils have been depleted through overuse and erosion, where some soils are just not fertile and friable by nature.

Many people live in urban environments where container gardening has to be practiced.

The use of added compost and substrates like peat moss is essential for growing plants to their full potential.

All these characteristics aid and improve nutrient absorption which in turn helps a plant to grow strong and healthy and produce good quality flowers and fruit.

grow some green

Disadvantages of Using Peat Moss in Your Garden

Not Environmental Friendly

Peat moss is harvested from peat bogs.

Peatlands are unique ecosystems (source) that are home to many endemic species of orchids, shrubs, carnivorous plants, and mosses.

They play a huge part in reducing greenhouse gases and are rich in carbon. Many birds nest here and mammals and insects hunt and feed in these peat bogs.

Considered a nonrenewable resource

This is a subject of great controversy.

Canada is the main supplier of peat moss for horticultural use while the other countries use it predominantly as a fuel supply.

Because of the sensitive subject of whether or not it is ecologically viable to support the peat moss industry.

I did some thorough research and I have to say, in my humble opinion, I see a lot of effort, money, and research has been made, not only to manage it but also to rehabilitate.

Pro tip: When buying peat moss, choose a trustworthy, well-established company.

A company that implements sound harvesting practices and has programs and initiatives in place that gives back to the earth and the community.

Not the cheapest choice

Sourcing a brand that is affordable and of a good standard is paramount. Because there are so many brands out there, often in the past.

I have found I’ve paid too much for too little or the quality is substandard.

The trick is to find a brand that is reasonably priced and offers a consistently good grade of peat.

Alternatives to Peat Moss in Gardening

If you are still not convinced that peat moss is the perfect soil conditioner to use or you want to experiment with other amendments you can try the following:

Related post: Peat Moss vs Coco Coir: Is Peat Moss Better Than Coco Coir for Gardening?

Whatever your choices are when it comes to great gardening just remember the main ingredient is love. And you can’t buy love!

Happy gardening!

Sphagnum Peat Moss – What It Is & How To Use It Wisely In Your Garden