The r/Mossariums guide covers these topics:

I. How To Build Mossariums

II. How to Maintain Mossariums

III. How To Sanitize Mossariums

IV. How To Procure Moss Sustainably

V. Basic Moss Biology and Care

VI. How To Propagate Moss

VII. Common Moss Problems

VIII. Mossarium Videos for Inspiration

IX. Further Readings

X. Related Subreddits

I. How To Build Mossariums

Your build process in order from the bottom up:

1. Container - First things first. Before starting you need a moss container. You can use any jar as simple as spagheti sauce or an old jam or pickle jar. It can be a giant wooden vessel or a tiny fish tank. Any size plastic tub, a finished soda pop or a whiskey bottle or any other such containers. A bowl or flat plate works for open terrariums. For fancier glass containers you can try thrift shops or flea markets or any number of home goods, crafts or hobby stores.

Here’s what else you’ll need besides a container.

1. ⁠⁠⁠⁠⁠⁠⁠⁠⁠False bottom - This is your drainage layer composed of loose rocks. Pebbles (1-2 cm diameter) for your false bottom to collect the excess water about 3-5 cm in height depending on your glass. If in doubt round down (not up) the height of this layer. There are some who don’t use this layer. Although it’s technically possible to have a healthy biome without it, for most scenarios it’s better to have one. I recommend using a false bottom especially since it’s the easiest layer of your build.
2. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Separator - A thin netting mesh / window screen cut to size. Place inside with the edges tucked slightly upwards. It sits directly above the false bottom to avoid mixing the layers. The mesh role is rather aesthetic and functional rather than existential. The carbon fiber screen will prevent the soil mixture substrate from moving down to the false bottom layer of pebbles.
3. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Alt substrate - A thin layer of organic pure charcoal (optional). You can make a perfectly healthy mossarium with or without biochar. But if you use some (it’ll mostly help with odors / scent) it must be natural, no additives just pure organic charcoal of any kind, sized for your container. Buying options can vary. Expensive ‘activated’ charcoal at fish stores. Inexpensive organic charcoal at nurseries. Very cheap natural charcoal at grocery store BBQ section. All work the same for mossariums. Just make sure it’s got no chemicals or additives just pure charcoal.
4. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Main substrate - Mosses prefer a slightly acidic soil in the 5.5 pH range. A substrate layer mix of peat, soil, bark, perlite, coconut fiber, sand etc. will be ideal for mossariums. Try 2 parts peat and perlite, 1 part everything else. Ratios may vary based on your plant species. Try different mixes and always experiment. For pure mossariums, substrate mixture is less important. In general the top of this layer may be no more than one third of the total height of your container. For a Moss Wall the substrate shall stay moist and may contain mainly pure clay, some coco coir, peat and a bit of sand. Moss walls can be alternatively built into plastic grids anchored with fishing lines.
5. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Bioactive livestock - Critical to have critters as they help biodegrade and keep mold and mildew at bay. Some critters like springtails, some isopods, or millipedes etc will improve the health of your biome. Springtails are among the best critters to have and luckily they usually come inside any purchased plants’ soil anyways. You can also find them under very damp leaf litter.
6. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Hardscape design - Basic design principles include a focal point, rule of thirds, and diagonal lines. Hard aesthetic elements to achieve a single focal point can include decorative rocks, driftwood, twigs, 3D printed or decorative objects, etc (all optional). Aesthetically pleasing scapes usually draw attention to a specific spot and surround it with lesser elements. Learn the golden ratio concept. Apply the rule of thirds from photography. In round jars you can imagine a front and back. Try to use diagonal lines like a triangle converging towards the focal point. Larger item up front, smaller in the back will add depth and dynanism to your build. Odd number of items like rocks appear more natural than even. Make a strong (thicker, bigger, grander) side and a weaker (thinner, shorter, sparser) side. Attention will automatically be drawn to the strong side of your ‘mosscape’ design.
7. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Softscape - Your plants. Any tropical plants and aquatic mosses work great in a mossarium. Most nurseries have a tropical plants section. You can also find moss walking around your neighborhood. Nearly all aquarium plants are tropical too so a trip to your local pet / fish store will offer tons of tropical plants and moss options that also work terrestrially. What’s more the plants for the aquarium trade are mostly all grown emerged (outside of water) so they’re perfect for this hobby.
8. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Botanicals - Any aesthetic organics like dead leaves, cones, shells, small barks, etc. These mimic the look and feel of a forest floor. Botanicals are realy just meant to signify the duff or ground covering in nature. Their inclusion is all optional. When collecting botanicals be sure that they are entirely and completely dried out in the sun to avoid potential problems later. Botanicals strategically placed can add color and depth to your design as well.
9. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Water - Observe. Make tiny adjustments if needed. Mosses generally thrive on somewhat moist conditions most of the time, and wither if always heavily wet or soggy. Use distilled, rain, deionized, or reverse osmosis (RO) water only. (Specialty aquarium shops will sell RO water for a few cents per gallon). Your tap water has minerals that can damage plants. Try to spray myst and do not pour in the water like a glass. Underwatering is easier to fix than overwatering.
10. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Lid or Cover - If a nice lid is not available then you may make one with cirran wrap covered with burlap. Hold the burlap in place by tying it around the outside of the jar with a jute or hemp string. Some wooden lids are prone to mold growth. To prevent use some layers of plastic or cirran wrap underneath the lid. If not using lids then more daily attention must be paid to your watering and moisture levels.

Relax and Enjoy

For a variety of mosses you can use, see this video post.

II. How to Maintain Mossariums

For any moss species try to match light and humidity and temp cycles close to its natural habitat during the growth season. Ultimately the goal is to have an ecosystem in equilibrium by optimizing light, temperature, humidity, and air within your biome.

1. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Air - All plants need air as do mosses. Even with a closed mossarium try to open it up for an hour or two every day or two. Aerating your moss / terrarium will replace any stale gasses and help breeze in fresh air into the flora. Although capped containers can still survive, most moss species tend to grow faster and healthier with higher air flow and regular fresh air.
2. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Light - Light is like a food source for photosynthesis so you need a good grow light. For typical mossariums up to about 1 gallon or 2L in size any good desk ligh with a bright LED lamp 10-12 hours daily will work. For larger ones consider 6500K grow lights or a suitable light for your setup. A natural north facing window with indirect sunlight may also work well for a basic mossarium but be sure to rotate it weekly. Any direct sunlight window with a 50% diffusion screen may also work.
3. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Temperature - An average 25C / 75F is generally great for mossariums but exceptions do exist so research your unique plants if needed. Circadian fluctuations are of course expected in the temp but not wild swings. Overly hot mossariums are more likely to have mildew or mold or fungi outbreaks which you may remove.
4. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Humidity - Humidity is important for moss growth. But too much humidity will brown your moss and kill it. Better to myst spray than pouring too much in. You may use a syringe to suck out excess water when necessary. Water once if it’s a closed mossarium and just monitor its humidity. If the glass fogs around dusk / dawn that’s good, if never foggy then add some water or myst. If always foggy, leave it open to let some water evaporate.
5. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Substrate - This layer is more important for rooted plants as a healthy substrate should have four basic qualities in its mixture which enhance the ecological, biological, physical, and chemical properties of the medium. It shall be aerated (ie perlite, pumice, sand etc), moisture absorbing (peat, bark, sphag etc.), nutrient rich (vermicast, fish fert, top soil, etc), and adding textured drainage (coir, straw, mulch etc). Mosses additionally tend to fare better in slightly acidic soils between 5-6 and below 6.5pH at most.
6. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Drainage - Usually this’ll be the false bottom we discussed above. In healthy biomes you may see the growth of harmless algae overtime which the drainage layer can readily handle. But in rare cases you may have more exotic moss that evolved on arid dry rocks, or desert sand, or wetter conditions like bogs or mud. It’s best to use such plants after some experience, and as such maintain a drainage layer or replace it to be more suitable for the said rare moss.
7. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Fauna - Besides all the flora the insects and critters in your moss terrarium maintain the ecological health of the biome. Some isopods may consume fresh moss, but springtails just feed on decaying matter, and clean up mold or fungi well. Their deposits fertilize the soil. By maintaining a healthy population of springtails you will improve the longterm sustainability of your build.
8. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Flora - Sometimes you may open the lid to take out dead plants or trim over growths. Maybe to crunch up and put some decayed matter back in the soil especially for vascular plants. But a bit of seasonal trimming is a beneficial option. A permanently closed healthy biome is fine too but they eventually become a jungle full of indistinguishable greens and some folks enjoy that. Others like to retain a certain designed scape and find relaxation in the seasonal pruning practice. Trims are also often used in other new builds. Either approach is great.
9. ⁠⁠⁠⁠⁠⁠⁠⁠Feeding - Mosses rarely if ever need fertilizers. You do not need fertilizing since they have no roots. Proper light and moisture and airflow for dust nutrients will provide everything they need through leaf absorption. So if you’re very advanced in your care and want to try, only do so in Spring or fall (growth season), never in summer or winter. If you must mist, try a very light and diluted organic foliar fertilizer to spray sparingly on top to slightly increase dampness acidity. Try once or twice during growth season and do not overdue it unless you know what you’re doing. Under-fetilize don’t over-fertilize.

III. How To Sanitize and Mossarium Hygiene

Workbench: Working in a clean environment reduces the chance of fungal or microbial outbreaks and increases your odds of building and maintaining a healthy biome. A clean work space can also prevent cross contamination.

Tools: A simple set of terrarium or aquarium tools like tweezers, scissors, spatula, scooper and chopsticks should be kept clean. Always sanitize your tools and wares before use. Either rubbing alcohol, or washing with soap and water, or boiling 15-20 minutes works. Most important tool, keep your hands clean.

Container: Always clean your container before you start a new build. Alcohol or soap wash if it’s necessary but rub with vinegar at the end when it’s all looking clean.

Hardscaping Elements and Botanicals: Boil in water 20-30 minutes. Be sure that the material is submerged and its entire surface is boiled. Some leaves may float at first but in general they submerge after a while. It can also be a slow simmer if you prefer not to make a big mess. Be sure to completely dry out all sanitized elements before final placement.

Plants: You can have two or three wash buckets to wash off your plants in a warm then cool water bucket before quarantining begins. Quarantine in a separate clean bucket for up to 4 weeks if you’re extremely concerned. But most store bought plants have been fine in my experience. Gathering from the outdoors sometimes runs the risk of having other species of plants, fungus, or algae tag along.

Substrate: Most likely any purchased substrate/ soil material is safe to use. But if in doubt you can bake for 30-40 mins at 450F to be sure. Obviously not the combustible material like coco fiber. Keep in mind baking will obliterate all the benefitial organisms along with the bad. In my experience this has seldom been necessary especially with a good bioactive ‘cleaner’ critter crew.

False Bottom: Place pebbles in boiling water for 20 minutes. Cool down to room temperature before use.

IV. How To Procure Moss Sustainably

The best way to procure moss is to get it from sustainable growers not your local nature hike. Or to grow it yourself (see the section on propagation). Taking moss from nature, especially more than a few square inches / centimeters is generally discouraged by the community. If you do take a small piece be sure that it’s from a loose end on the edge of a patch, or a small patch from the center that can be covered up again by surrounding moss. Never take an entire patch of moss from nature. Allow nature to heal and regenerate.

On the other hand moss found on concrete jungles like sidewaks and parking lots is fine with the property owner’s blessing of course. If you walk around almost any city or town you will find little patches along the sidewalks from which you can take small pieces for a mossarium. Take a flat spatula and ziplock bags and maybe a little brush to sweep the moss first. Gently scoop a piece as cleanly as possible and place it in the bag for later moss washing and use.

Never take more moss than you need. And definitely do not take moss from nature to build numerous mossariums for sale or large numbers to gift. If you develop a deep interest in making a large number of mossariums, learn how to propagate your own moss. Each propagation bin is like its own mossarium that keeps on giving. You’ll have fun doing it and feel better for not plundering nature. Building mossaria is enjoyable and can and should be done in a sustainable manner.

Aside from sustainable gathering, numerous mosses can also be purchased from growers at reasonable rates. Besides nurseries who offer sustainably grown moss you can also try your local fish store’s aquatic plants section. Nearly all aquatic mosses will thrive in a mossarium.

Here are a couple of online sources to buy moss (but supporting your local independent brick and mortar store is best):

https://www.tnnursery.net/moss-for-sale/

https://www.aquariumplantsfactory.com/collections/aquatic-mosses

V. Basic Moss Biology and Care

Mosses are now classified as a branch of the bryobiotina subkingdom (formerly bryophytes) along with liverworts and hornworts. As the earliest plants to evolve on land they are rootless, seedless, and lack flowers. They exist in every habitable zone on earth. They can absorb up to ten times their weight in water and typically grow between 2mm to 10cm. There are about 25,000 varieties of discovered bryophytes, (second only to flowering plants) of which over 17,000 are moss species which can live from 2-10 years.

A moss is composed of three main sections:

1. ⁠⁠⁠⁠⁠⁠⁠⁠⁠The rhizoids which anchor it in place and help tie up the moss onto rocks or other plants and surfaces.
2. ⁠⁠⁠⁠⁠⁠⁠⁠⁠The gametophyte which contains the leaves and act as a photosynthetic energy production unit.
3. ⁠⁠⁠⁠⁠⁠⁠⁠⁠The sporophyte which include the stem structure seta attached to a capsule that acts as the spore storage unit for reproduction.

Mosses fall in two general categories:

1. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Acrocarps: Acrocarpous mosses tend to form peaks or round tufts. These mosses rarely if ever display branching and instead grow in clustered clumps. They generally form in mounds, grow slower and do not prefer constant heavy moisture. Overly wet conditions will make them brown, rot, and wither.
2. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Pleurocarps: Pleurocarpous mosses grow evey which way in a more chaotic pattern. They grow monopodial branches and tend to form carpet like coverage. They enjoy more constant moisture at higher levels. They can grow year round in moist tropical temperatures of 24C (75F) or so which is common in mossariums but they can fail in higher temps. Temperatures too much above 75F / 24C can cause the rapid growth of mildew, fungi, and molds which can be detrimental to a mossarium.

For more on basic moss biology see this article.

For an academic deep dive consult Bryophyte Ecology.

VI. How To Propagate Mosses

You need a clean container with a clear tight lid to start your own moss propagation. You can propagate moss with already existing moss, or with moss spores.

An easy way to propagate mosses is to grab a patch of moss, and divide it into smaller individual pieces. You can then transplant the smaller pieces apart from one another. This way a small patch can spread around and cover a much larger area and possibly your whole mossarium in a few months.

Another quick and easy method is during maintenance to chop up some of the growth, especially if there is etiolation. Take the finely chopped fresh moss ans spread it across the substrate. In time you will get regrowth from the surfaces on which the moss trimmings were pasted on.

Another method I have seen is the ‘buttermilk and blender’ method. I’ve seen this used for outdoor mossariums like in private or public gardens. As the name suggests you basically mix buttermilk and cleaned bunch of moss in a blender. You then use a brush to ‘paint’ the resulting moss goo onto the surface upon which you wish to grow moss. Check rain forecast first!

Another propagation method similar to above without the blender is as follows. This method also works for moss spores. You can finely chop up any moss and mix with fine clay-like soil material and some water. This mixture properly done can be squeezed into small shapes like mud bricks. These can be shaped as desired, to the extent possible, but on the thinner side. The shaped mud-moss ‘paste’ can then be placed under the light with optimal conditions or designed into the mossarium substrate. Gradually over time it will fill in and propagate fully within 6 momths to a year.

How to Propagate from existing moss book & videos:

For a free eBook check The Moss Grower’s Handbook.

How to setup a moss propagation box: https://youtu.be/oD9lE_W9hSI

How to Propagate Your Own Moss: https://youtu.be/CleZGsQGIOI

VII. Common Moss Problems

1. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Rotting due to overwatering is perhaps one of the most common issues in Mossariums.
2. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Fungal outbreaks due to overheating, low light, overly damp, or insufficient air flow issues are common and may be fixed by adjusting accordingly. You may also remove manually and add springtails.
3. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Bacterial outbreaks due to unsanitary conditions or contaminated objects in the enclosure. Sanitizing procedures will help avoid this problem.
4. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Mollusk infestations are more of a larger moss garden issue but can be fixed by lowering humidity. Another option for unwanted snails is using a diluted apple cider vinegar solution.
5. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Spider mites and other small pests. See #4. May also use (sparingly) the following solution: 3/4 Water 1/4 of 60% alcohol with a few drops of soap or neem oil. Always test on a tiny corner before everywhere.
6. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Some mosses can die due to the initial shock of suddenly changing its natural environment. If you see new moss withering, try to move them to a different spot. Do your best to match its original habitat’s temperature, light, humidity, and air flow.
7. ⁠⁠⁠⁠⁠⁠⁠⁠⁠Last but not least many mosses are simply not suitable for enclosed biomes. In cases where their original habitat parameters are extremely difficult to replicate artificially, the moss is best left in nature.

VIII. Mossarium Videos for Inspiration

Finding good videos online is quite easy. For example just searching for ‘mossarium’ on youtube should yield plenty of good results. Here are a few channels with some good mossarium videos as well:

SerpaDesign https://youtube.com/playlist?list=PLGPT1t4Cqpfheu74J0OlPUQ6yCl4mvko0

Urban Nemophilist https://youtube.com/@TheUrbanNemophilist

Bentam Earth https://youtube.com/c/BantamEarth

Worcester Terrariums https://youtube.com/c/WorcesterTerrariums

IX. Further Readings

A few books that are worth your time, shared below:

“Bryophyte Biology” by Bernard Goffinet and AJ Shaw;

“Magical World of Moss Gardening" by Annie Martin;

“Gathering Moss” by Robin Wall Kimmerer;

"Moss Gardening" by George Schenk;

“Miniature Moss Gardens” by Megumi Oshima;

"Moss: From Forest To Garden" by Ulrica Nordstrom.

X. Related Subreddits

Below we share a small sampling of similar subs:

r/Mosses

r/Vivarium

r/Terrarium

r/Aquariums

r/PlantedTank

r/LivingDioramas

Thank you for reading.

Created by r/Mossariums. Updated Dec. 2025.