Fern Moss (Thuidium delicatulum)

The term Fern moss refers to several varieties of species of terrarium plants in the Thuidiaceae family and Bryidae subclass.

There are a number of moss species in the Thuidiaceae family that are often referred to as Fern moss.

Just like their name suggests, these plants have fern-like branches that give them the appearance of a traditional fern plant.

This article will specifically cover the Thuidium delicatulum species.

Quick Stats:
Scientific Name Thuidium delicatulum
Common Name Delicate Fern Moss, Thuidium Moss, Sheet Moss, Log Moss, Common Fern Moss
Family Name Thuidiaceae
Habitat Wetlands
Temperature 28°F to 70°F
Height 24 inches
pH 5.0 to 6.0
Lighting Low to medium

What Is Fern Moss?

The scientific name for Delicate fern moss is Thuidium delicatulum. It belongs to the Thuidium genus under the order of Hypnales.

Thuidium delicatulum is a terrestrial moss and does exceptionally well in very wet soil.

Despite their liking for wet environments, this moss should not be fully submerged or left to sit in water.

Delicate fern moss is commonly used by hobbyists to decorate and accentuate lower land areas of their vivariums.

Fern Moss Facts

Besides Fern moss, Thuidium delicatulum is also referred to as Delicate thuidium moss, Delicate fern moss, Sheet moss, Log moss, and Common fern moss.

This moss can bond to surfaces extremely well and can usually be seen adorning living or dead branches, rocks, logs, stumps, or damp soil.

Another interesting fact about Thuidium delicatulum is that it is often used by birds for nesting material.

Its large size and dense carpeting ability also make it a great protective cover for small vertebrate animals and critters found in woodlands.

Delicate fern moss is a fairly easy moss to care for and requires little maintenance.


Delicate fern moss looks like an assortment of tiny ferns. They have wide triangular leaves and the stem leaves are usually larger than the branch leaves.

The leaves have very small thread-like branches on them and tiny bumps within the cell walls of the plant.

Delicate fern moss may range in color from yellow-green, bright vivid green, deep darker green, and even orange-brown.

A dull orange or brown color is usually a sign that the plant has dried out and is dying.

Just like many other mosses, this plant uses rhizoids to grip and attach itself to surfaces that it lays on.

It can grow up to 2 feet tall and outward up to 18 inches wide.


Thuidium delicatulum is a widely distributed moss. It is native to wetlands and shaded woods of North America, Asia, Europe, and South America.

Delicate fern moss is also very common in certain parts of Illinois.

Within the state, it can easily be seen in hillsides, wooded bluffs, tree trunks, shaded creek banks, stones, swampy woods, and even dead pieces of trees. 

As long as it has plenty of water and a shaded area to grow in, Thuidium delicatulum can survive in a wide range of temperatures.

pH Preference

Like many mosses, Delicate fern moss tends to prefer to be on the more acidic side of potential hydrogen.

In the wild, this plant is often found on very acidic soil or rocks with highly acidic surfaces. Ideal pH levels will be in a range of 5.0 to 6.0 but this moss can survive more neutral levels.

Vivarium Type

This type of moss will do great in a variety of vivarium types. When deciding if rather or not to use this moss in a particular type of enclosure, be sure to go with setups that have terrain areas elevated from constant water sources.

Here are recommended vivariums that this moss will do well in:

  • Paludariums – Half aquatic/ half terrain-based enclosure.
  • Ripariums – Mostly aquatic-based enclosures with some terrain features present.
  • Terrariums – Fully terrain-based enclosures with little to no aquatic features.

Vivarium Placement

Thuidium delicatulum is a terrestrial-based plant. It will not do well partially submerged or fully placed underwater.

However, it will flourish in a very damp or even wet substrate as long as it has proper drainage.

This plant can be placed in the foreground of the vivarium as well as attached to rocks, logs, or other surfaces.

Its natural ability to carpet makes Delicate fern moss the perfect plant to cover up unattractive areas of a vivarium.


Delicate fern moss has the ability to grow and thrive on a wide variety of surfaces.

Due to its shallow root structure and unique way of absorbing nutrients, it can pretty much attach itself anywhere.

As long as the substrate or surface is moist and the moss receives an adequate amount of acidic water, there is nothing to worry about. 

Some types of drainage will also be important when it comes to this plant. If the ground is too wet and the moss ends up sitting in water, it will eventually die.


The woodlands that fern moss is native to provide a perfect umbrella of shade for this moss to adequately grow in.

This plant likes medium shade to partial sun. Exposing it to direct sunlight for long periods of time will burn and dry out the moss.

When setting up lighting inside a vivarium for this moss, a high level of brightness would be ideal.

It will also be a smart idea to keep the tank away from any type of artificial light that produces UV. Cooler color LEDs that simulate a cloudy day will be the suggested way to go.

Buy Fern Moss

When shopping for possible Delicate fern moss, expect a few key indicators you are buying the best quality plant. The moss should be snail free along with any other type of pest.

The source of moss will usually be sold in small tissue cultures, ready for you to propagate. The batch should arrive fairly moist and in fairly good shape.

Click the image below to find out more about the current price and other relative info:

Fern Moss Care and Propagation

Thuidium delicatulum are pleurocarpous plants. This means that instead of growing upwards, it grows outwards and to the sides.

If the plant is cared for correctly, it will develop spores that blow off and allow for new growth.

How to grow

Delicate fern moss is a self-fertilizing plant but is not limited to. The plant will continue to spread on its own using its spores or by being tracked to other areas by small critters.

However, it can also be propagated through the method of division.

The parent plant can be carefully broken off into smaller pieces and transplanted into other areas.

These pieces should then be pressed firmly over the damp substrate. Once Delicate fern moss is established, it will begin growing into a carpet and spreading rapidly.


As mentioned before, Delicate fern moss is a terrestrial plant that requires very moist growing conditions.

The soil or surface on which it is growing should be kept constantly damp.

The best-case watering scenario would be to heavily spray moss when you see signs of dehydration. Do not let Delicate fern moss dry out between each watering.

Plants Similar To Fern Moss

Adding diversity to an enclosure is key to an aesthetically pleasing enclosure. Try mixing up the look of your vivarium with different flora that can easily co-exist in the same types of environment.

Furthermore, if for some reason you find this moss hard to acquire or would like to consider something similar to this plant…

Here are some other plants you might find may do well with or in the place of Thuidium delicatulum:

Taiwan Moss (Taxiphyllum Alternans)
Liverwort Monosolenium Tenerum
Phoenix Moss Fissidens Fontanus


I absolutely love the look Delicate fern moss can give a vivarium. It is a great tool to use to help dress up and brighten any enclosure.

Thuidium delicatulum would be especially perfect for a woodland or forest-style terrarium.

I definitely wouldn’t want this kind of terrarium moss for extremely dry, desert-themed builds. I would, however, recommend it for very moist builds that want to go for a tropical look.

Frequently Asked Questions

Fern moss, also known as Thuidium delicatulum, is a small, lowgrowing fern species commonly found in areas of high humidity throughout the Northern Hemisphere and parts of Central America.

No, Fern Moss (Thuidium delicatulum) does not need soil to grow. This type of moss will grow directly on a variety of surfaces such as rocks, logs and trees without the need for soil. It requires moist but not overly wet conditions and is only cap

Fern moss typically produces new fronds and grows quickly in the right environment often around 1 inch per month. It typically achieves maturity at around 69 months after planting.

Thuidium delicatulum, or fern moss, should be watered once a week, or enough to keep the soil constantly damp.

Yes, Fern Moss can live in water. This species is typically found on wet or moist rocks, logs and humus in areas that receive ample water and sunlight. It does well in both shallow and deep water.

Yes, fern moss can spread. It makes use of short rhizomes that can send out small plantlets from old growth in order to spread, similar to most other forms of moss. 

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