Is Peat Moss Good For Bonsai?

bonsai with peat moss
Peat moss can be very beneficial for bonsai - especially when used within the soil mix as it has effective water retention capabilities. Whether you’re growing a bonsai tree or interested to know more about bonsai as an art form, this article explores what bonsai is and the benefits of using peat moss for its cultivation.

What is bonsai?

Bonsai comes from the Japanese phrase meaning (in its literal translation) “planted in a container”. Bonsai itself is essentially an art form that originated from ancient Chinese horticulturists, and then became popular within Japanese Zen Buddhism. Like moss, which along with bonsai is the focus of this article, bonsai has been around for over a thousand years.

Growing a bonsai tree or plant is intended to create a miniature representation of nature. So that’s where the practice involves pinching buds, pruning and wiring branches, and carefully restricting the use of fertilizers in order to limit or redirect healthy growth.

A bonsai plant isn’t genetically dwarfed - even though they tend to be kept under a metre in height. Plants with smaller leaves naturally make it easier to achieve a bonsai composition. However, any plant species that grows true branches or has a woody stem or trunk can be grown in a container for the art of bonsai.

So where does peat moss come into this?

What is peat moss?

Peat moss has grown in popularity since its introduction to gardeners in the mid-1900s. This is primarily down to its ability to retain water, which makes it effective in holding nutrients that would otherwise leak from the soil.

Peat moss consists of decomposed material that occurs as a result of other living organisms, including other mosses, dying and decomposing in peat bogs. Peat moss takes a long time to form - often over thousands of years. It is inherently different from standard types of compost that gardeners usually use when growing and cultivating their plants, as it is primarily composed of moss.


Soil is essential when it comes to cultivating an aesthetically pleasing bonsai plant or tree


How to use peat moss with bonsai

Soil is essential when it comes to cultivating an aesthetically pleasing bonsai plant or tree. However, the type of soil you use is incredibly important. It’s often not simply a case of turfing soil from the garden and potting it to grow the bonsai plant or tree.

When it comes to using peat moss with bonsai, it’s necessary to get an understanding of the two soil mixes used in growing bonsai - organic and inorganic. Both mixes are designed around water retention, the key difference being that one consists of organic components such as decaying plant matter, whereas the other consists of rocks and other gritty material.

You might wonder: can peat moss be mixed with soil? The simple answer is yes, and in the case of bonsai growth, peat moss is a key ingredient to organic mixes. It’s ability to retain water is so efficient that it should be used sparingly to ensure it doesn’t retain too much of the water. It plays an important role in binding the other material together and keeping everything in position as the roots grow. However, since it can retain water for a long period of time, it’s important not to overuse peat moss in the soil mix.

Why is drainage important for bonsai?

Healthy bonsai plants and trees rely on sufficient drainage. Whilst sphagnum peat moss possesses excellent water retention abilities, overloading it into the soil could actually inhibit the bonsai plant’s growth and in some cases cause it to die. Try not to be tempted to maintain a high percentage of sphagnum peat moss and use more holes in the pot, thinking that using extra holes will help with drainage. While it’s true that the holes will release the fluid, sphagnum moss will always have the ability to retain water effectively. So the ability for a bonsai tree or plant to achieve effective drainage comes down to an efficient soil mix.

Benefits of peat moss for bonsai

As previously mentioned throughout this article, peat moss can retain water extremely well. Perhaps one of the lesser known facts about peat moss is that it has a high zinc content, which means it also contains the naturally occurring antibiotic known as Tropolene.

Sphagnum’s antiseptic properties help combat the anaerobic bacteria that can often cause wood to decay - so it is essentially a natural healing agent. That’s why pure sphagnum can be a truly effective solution for nursing weak trees back to health, as well as trees that have rotted roots.

These antiseptic properties that occur naturally in sphagnum have been known to humans, not just gardeners, for hundreds of years. So while we might use it for our gardens now, it was historically used as a natural bandage to soak up blood that leaked from open wounds. In fact, it played this very role during the brutal global conflict of the First World War (which was before my time in case you were wondering!). So as well as offering a beneficial role to the cultivation of bonsai plants and trees, sphagnum moss is quite a remarkable, resilient plant.