The secret to creating an adorable bonsai display lays on the base surrounding your bonsai tree. Bonsai is, after all, the art of creating a miniature forest.
How big a bonsai grows lays in the hands of the gardener. You decide.
The size of the bonsai tree will, in part, determine which type of moss is best for the bonsai. Generally, only a fraction of the trunk should be surrounded by moss.
Asides from beautification, moss plays an important role in bonsai care.
It is a natural insulator and holds a lot of moisture.
There are thousands of moss species, but only two types. Acrocarpous mosses grow taller. Pleurocarpous grows wider.
To create a dense mat for ground covering, the majority of the moss will be a type of Pleurocarpous moss species.
These are carpet mosses used for ground covering.
Read on to discover how you too can say bye-bye to the dull brown of soil by giving your bonsai a living forest floor.
Silver moss, big star moss, starburst, and sheet moss (hypnum cupressiforme) make ideal soil coverings for smaller bonsai. Medium to large bonsai trees may be able to accommodate the larger growing fern mosses that grow upwards of 4-inches. Mosses can be mixed to beautify the base of a bonsai.
Match the moss to the type of Bonsai
Like all plants, different types of moss require different soil acidity. Most prefer the soil pH to be between 6.0 to 7.0, but some do prefer acidic over alkaline or vice versa.
The simplest way to determine the type of moss that is best for bonsai is to match the soil pH requirements.
As an example, the Golden Gate Ficus Bonsai prefers a soil pH of 6.0 to 6.5. If you’re growing a bonsai for a cutting, the soil pH will be higher at around 6.5 to 7.5.
That will limit the types of moss that could be grown unless it’s grown from cuttings grown indoors.
Indoor growing and transplanting will be required for most types of moss that are harvested from the wild. If you want to buy packets of moss spores to grow directly on the topsoil, it is best to match the pH requirements.
Types of mosses for decorating the topsoil of bonsai trees
Atrichum moss is from the Polytrichaceae family. The leaves on this are hairless, triangular, and shaped like miniature stars.
The type you grow determines the height it reaches.
- Big Star moss, sometimes called Catherine’s moss or Common Smoothcap moss is the Atrichum Undulatum species. This reaches heights up to 3-inches.
- Starburst moss is the Atrichum Angustatum species, a miniature variety that grows up to an inch in height.
These are considered to be a type of mood moss because they change color.
When it has enough water, the leaves are a deep shiny green. When it dries up, it shrivels and the leaves turn maroon. The greenery returns once misted.
These are a clumping moss type meaning it grows upright rather than spreading across the topsoil.
This is best suited to bonsai trees that are kept in partial shade. It is tolerant of a range of soil types. The only soil requirement it has is for the soil to be fast draining while maintaining adequate moisture.
Silver moss (Bryum argenteum)
Bryum argenteum, commonly called silver moss is suited to most soil types including alkaline soils. It is a type of carpet moss so expect more horizontal growth than vertical.
The leaves are typically 1cm tall but can grow to 5cm if they aren’t trimmed later in the year outdoors.
Indoors, they remain small. Each stem can spread two inches though which is why this is referred to as carpet moss.
The tips of each tiny leaf are translucent giving each stem a silvery appearance.
Due to the small size of each stem and the translucent tips on each, the other term given to this is the silver-thread moss.
If you grow moss indoors from cuttings, the soil is often more alkaline with a soil pH of up to 7.5. For those soil types, silver moss would be the ideal carpet moss to cover the soil around a bonsai tree.
Sheet moss (Hypnum cupressiforme)
Hypnum mosses are traditionally found on the ground in forests. The base of a bonsai is perfect for this type of moss. Provided it is Hypnum cupressiforme, which is the sheet moss species.
Sheet moss typically grows between 1 and 4 inches, but to get it taller you need to focus on growing it. Leave it naturally as a ground covering in the shade, it’ll remain as a carpet blanketing the soil, rather than growing vertically.
The taller hypnum variety is Hypnum imponens, which is the Feather moss. This type can reach a height of 8 inches.
To maintain a smaller ground covering moss, use hypnum cupressiforme. It favors soil acidity of 5.0 to 6.5, but it can tolerate soil with a neutral pH of 7.0. Any higher, it will struggle.
Making the most with bonsai moss
With so much variety of mosses available and the ease of transplanting, learning about how to grow moss in a terrarium will give you multiple types on demand.
The display can be changed up anytime, keeping your bonsai looking terrific all year.
Keep the carpet mosses on the soil, transplant some lichens, fern moss, or perhaps decorative mosses with colorful sporophytes to brighten up the base.
Even if you do plant a type of moss that you find you are not keen on after a month or two, it is never permanent. They can easily be removed and replaced with a different moss species.
Frequently Asked Questions related to which type of moss is best for bonsai
Can fern mosses be used with bonsai?
The common fern moss (Thuidium delicatulum) produces leaves up to 3.5 inches in height. They may be suited to larger bonsai trees around 30-inches and over. The tallest of small bonsai trees are just 10-inches. Fern moss could cover over a third of the tree’s trunk making it look overgrown.
Should moss be grown on the soil or transplanted around a bonsai?
It is easier to grow moss indoors and transplant it when it has reached a suitable size. By transplanting, you can grow multiple moss species and lichen plants, transplant them onto the topsoil, tamping them down with a tweezer spatula.