Moss is one of the hardiest plants on earth. It is also one of the oldest. If any there is a plant that is fair game for a science project, this is the no-fail plant to grow.
Consider it a zero-tear plant for the kids to grow that has the highest success rate.
The only three things required to grow moss indoors are a little bit of sunlight, watering, and warmth.
An airtight container, a few basic supplies, and a window that gets good sunlight will get the process going.
Moss will grow chemical-free. No fertilizer is needed. It is also highly resistant to pests, mainly because it has no roots, and it is so small that there is no nutrient value to them. Pesky bugs pass on by because they have no reason to try to eat moss.
Besides, moss evolved from algae. Only nematodes can derive nutrient from moss.
To make your growing experience as smooth as it can be, every detail you need to know about growing moss indoors is covered below.
Moss can be grown indoors with just two hours of sunlight per day. It needs a closed container, humidity at 70% or higher for the fastest growth, and temperatures between 60 and 90-Fahrenheit. (15 to 32 Celsius). It does not need fertilizer, but can be coaxed with a diluted mix of skimmed milk.
Moss care indoors
Moss is extremely easy to care for. The only thing to remember is that they need sufficient lighting. A shaded corner will not suffice.
Without at least two hours of bright light, photosynthesis will not happen. That will prevent the moss from growing.
Moisture, humidity, and light are three essentials that moss needs to grow. Once grown and established, it is very hard to destroy.
It may lose its greenery when it becomes stressed, however, it is a resilient plant that quickly bounces back when conditions are restored.
Moss is tolerant to all soil types. It grows fastest in acidic soils with a pH range of 5.0 to 5.5. Any soil will work though. Regular potting soil or alkaline soil. Moss is highly adaptable. Growth is faster in acidic soils.
Moss is shade tolerant, but it does use photosynthesis so it will require a daily dose of sunshine to grow. The morning sun has the brightness minus the heat intensity. Moss can cope with heat so direct or indirect sunlight will work.
For an easier understanding of how light levels for plants works, direct sun is the hottest and brightest. Plants get this light level from being placed on a windowsill.
Indirect light is when the rays of sunlight bounce off something before reaching the plant, reducing its UV rays. Growing indoors on a desk or a side table under a lamp, the light should be bright enough to provide heat and placed around 12” above the container.
Water with rainwater or distilled water. Young and weak growth can be stunted by contaminants from unfiltered tap water. Water contaminants can prevent nutrient uptake causing the moss to turn brown. As these are grown in containers, they need very little watering. Only a few teaspoons of water weekly.
The equivalent of a light misting with a spray bottle a few times per week.
Moss grows in all sorts of temperatures. The lower the temperature, the slower it grows. Ideal temperatures are 60-Fahrenheit to 90-Fahrenheit.
All types of moss favor high humidity above 70%. They do not tolerate low humidity levels. They hold a lot of water and slowly release it, which is why placing a base layer under the soil in is how to grow moss in a terrarium.
The same setup can be achieved by using any sealed container.
The water is recycled so that it slowly moistens the soil and the moss from below continuously bumps humidity up.
Moss does not need fertilizer. They do need nitrogen for photosynthesis. When growth is particularly slow, the soil can be acidified slightly with milk mix. This is made with 1 part dried/powder skimmed milk mixed with 7 parts of water.
Decide on the types of moss you want to grow
Some are carpet varieties; others are climbers or trailing mosses.
Various types are covered below.
As a general guideline, for a large flat covering, grow carpet mosses.
To fill in holes in a rock garden, or fill spaces in a succulent terrarium to bump humidity up slightly, grow climbing varieties.
These can be bought from online nurseries, marketplaces, or arts and crafts stores.
If you have moss growing in the garden, or some species of it are growing in your neighborhood that you are allowed to pick, harvest some to grow.
Harvested moss will need to be washed in clean water to knock away any hitchhiking bugs, larva, fungi, and bacteria.
If you buy these, make sure you buy a living moss. Arts and crafts stores and several larger online marketplaces sell preserved moss.
Preserved moss is dried moss to use in crafts projects. They contain chemicals, can be dyed green and will be difficult to get growing again.
Living moss will be ready to plant.
Get your containers ready
Containers do not need to be deep. They do need to be clear and they can be plastic or glass.
If you have empty glass jars or transparent cups with clear lids laying around, they will be ideal for growing moss.
They do not need drainage holes. They do need to be airtight.
The exception to be being entirely clear is for glass bottles. The neck of the bottle will still let in enough sunlight and the glass will trap the heat.
Do not use green or brown bottles. Only clear glass.
Gather the materials
Multiple layers are needed inside containers.
The first is gravel or sand. You can buy horticultural sand, aquarium sand, or even play sand. Multiple colors are available.
Failing that, take a stroll by a riverside to gather some stones. Decorative pebbles can also be purchased online or locally.
Like with harvesting moss, sterilize rocks that have been picked locally before using them. Wash stones with bleach to get rid of any fungus or bacteria growth.
Optional: Purchase horticultural activated charcoal to filter tap water and remove toxins.
Have a suitable divider for each container
A substrate divider is used to keep the soil above the gravel or sand base.
This can be insect netting or a one-inch layer of wood chips or bark. The only requirement is that the material is porous. It needs to hold the weight of the soil above the gravel (or sand) and let water through.
Any soil is suited for growing moss. The more acidic it is, the better moss grows. Sterilize the soil before using it with moss to prevent mold growth once the container is sealed.
How to Plant Moss indoors in a container
Build your container up like a multi-layered jigsaw.
- Lay the foundations with a 1-inch layer of gravel or sand
- If you decided to use activated charcoal, add that to the base
- Add in the insect netting or a 1-inch layer of bark or wood chips
- Layer 2-inches of sterilized potting soil
- Plant your moss on top, gently pressing it onto the soil
- Mist lightly with water
- Put the lid on the container
Repeat the process with as many types of moss as you plan to grow, and label each container so you know what each moss is.
When to plant moss indoors
Moss can be grown indoors at any time of the year.
It only needs a couple of hours of sunlight per day. The micro-climate inside the airtight containers is how it grows no matter the season.
Pleurocarpous moss (carpet or sheet moss)
Pleurocarpous moss is the spreading type. These are mostly referred to as carpet mosses.
Popular types of carpet mosses include:
- Spoon Leaved Moss
- Baby tooth moss
- Plume moss
- Shiny sexy moss or seductive moss. Seriously! The scientific term is called is Entodon seductrix.
Acrocarpus (climbing or trailing moss)
Acrocarpus moss types are those that grow on a single stem without off-shoots branching from the side.
These can climb up or trail down depending on where they are planted. They grow on the bark of trees, on rocks, and on river stones.
Common varieties of Acrocarpus mosses include:
- Cushion moss or pillow moss
- Mood moss
- Fire moss
- Haircap moss
- Juniper moss
- Woolly fringe moss
Mosses that are not mosses
To confuse matters, some plants have “moss” in their name but grow nothing like them.
Examples of mosses that are not a “true” moss include:
- Reindeer moss
- Canary moss
- Caribou moss
- Fern moss
- Snake moss
- Ball moss
- Spanish moss
Moss is very easy to propagate. It is asexual so can use fragmentation for reproduction. It can grow from spores and from planting the rhizoids in soil, or another substrate.
Although a slow grower, each piece of moss planted in a sealed container will grow upwards and spread.
How fast moss grows depends on the species and climate.
Most Pleurocarpous moss types put on new growth after 6-weeks to 3-months. These can double in size after 6-months.
Acrocarpous moss is a slow-growing variety. These can take around 6-months to anchor into new terrain. Once attached, most types take between 6-months to 2-years to reach their mature heights.
Mosses only grow to a few centimeters in height.
Depending on the size of your containers and how you use moss, pruning them may be required to keep them looking their best.
They can easily be cut with scissors, or pieces pulled away on climbing varieties or torn from sheet mosses.
When pulling or tugging, the only thing to be careful with is lifting the moss off of the soil.
The rhizoids are shallow so it does not take much to lift these out of the soil.
For safe measure when pulling or tearing, use two hands.
One hand to hold the sheet or surrounding rhizoids onto the soil and the other to prise off the part of the plant you want to remove using your thumb and forefinger.
Moss is cold-hardy. At worst, it goes dormant. Once exposed to heat and moisture, it regains its greenery.
Indoors, it will remain green throughout the year.
Moss pests to watch out for
As moss has no nutrient value, it is highly pest resistant. Aphids, thrips, spider mites, and other sap-sucking plant pests tend to pass moss by – when it is grown alone.
Problem pests can be attracted to the high moisture content.
This can become a problem when the moss is introduced around other plants, such as a flower beds, hanging baskets, or wrapped around the roots of plants being planted in soil in an open terrarium.
Most species of moss can hold up to 10x their weight. That makes them attractive to nuisance pests. In a flower bed, or wrapped around the roots of succulents, insects may find the moisture and warmth attractive enough for nesting.
Carnivorous plant terrariums decorated with moss can become problematic as those plants produce nectar attracting the pests. Carnivore plants do not control pest outbreaks. The plants will feed on the occasional pest, or they get fed dead insects.
The majority of bugs that hatch from eggs do not harm the moss. They are more of an annoyance. Like fungus gnats, whiteflies and mites.
Whilst indoors, they will get little nutrients from the moss. Once eggs hatch though, they can latch onto other houseplants. In that sense, moss can be a harboring ground for larvae that introduces problem pests to your other plants. It is amazing where houseplants get bugs from. Some co-exist.
In a fairy garden or moss garden, growing moss is mostly pest resistant. At least to the ones that would damage plants.
The majority of problems with growing moss indoors is not insects, but fungus and bacteria. For that, insects help you grow moss indoors.
Common problems with growing moss
Moss turning brown
Moss turns brown if it needs to be watered.
Moss turning yellow
Moss turns yellow when it is not exposed to enough light.
Fuzzy mold growth
Fuzzy mold is the biggest concern because of the high humidity and temperatures required for moss to grow. Mold germinates in the same climate.
In a sealed enclosure getting rid of mold requires the use of beneficial bugs. Springtails are commonly used to keep down decaying plant matter.
The more insects feed on the debris, the less decaying matter there is for mold to grow on.
Airing the containers out once monthly for at least 20-minutes is enough to keep mold spores at bay.
Keep in mind, the containers will be getting some airing each time the lid is removed to mist the moss.
Algae grow similar to mold; however, this is more likely to climb up the walls of a sealed container, rather than on the moss. It will alter the humidity levels so it should be removed.
Like mold, beneficial bugs including springtails, isopods (pill bugs), or arthropods can keep algae under control.
Fun Facts about moss
- Moss is the oldest plant ever. Thousands of years ago, moss was nature’s carpet… Trampled on, and probably eaten by the biggest reptiles to roam the earth before us. Dinosaurs.
- The moss species is an extremophile – it survives in extreme temperatures, humidity, acidic soils, alkaline, and even the frozen glaciers in Antarctica.
- Moss is cryogenic. It dies back in extremely cold weather, but the spores do not die. Ever tried killing moss on a lawn? It always returns.
- Moss evolved from algae. That is how adaptable this plant is.
- Moss has no nutritional value so animals do not eat it. The one exception is reindeer moss (technically a lichen plant). Reindeer moss provides as much as 94% carbohydrates to a reindeer and it is only the reindeer that can digest it. The energy they get from lichen moss warms their stomach, helping them survive freezing winter temperatures.
Frequently Asked Questions related to growing moss indoors
Can moss indoors be transplanted outdoors?
Moss acclimates easily to all climates. It can be grown indoors to be used anywhere. It does hold a lot of moisture, so be wary of where it is used due to how heavy it can get when wet, such as if you line the roof of a garden shed with moss.
Can you grow moss indoors without soil?
Moss grows on any substrate. Soil helps increase humidity, but it has no nutrient value for moss. As moss has rhizoids, anything it can attach its rhizoids to is a suitable base. It will grow without soil.
Marcel runs the place around here. He has a deep passion for houseplants & gardening and is constantly on the lookout for yet another special plant to add to his arsenal of houseplants, succulents & cacti.
Marcel is also the founder of Iseli International Commerce, a sole proprietorship company that publishes a variety of websites and online magazines.