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How to Setup an Iwagumi Style Terrarium? Step by Step guide

How to Setup an Iwagumi Style Terrarium

During a quiet afternoon in my sunlit living room, I found myself mesmerized by the single, striking rock sitting atop my coffee table: a souvenir from a recent trip to Japan.

This simple stone, with its smooth surface and intriguing asymmetry, sparked an idea: why not create a miniature landscape that captures the serenity of a Japanese rock garden?

This thought led me down a path of exploration, culminating in my first attempt at an iwagumi style terrarium. It was a process filled with trial and error, from selecting the right plants to finding the perfect balance of rocks.

Yet, the peace it brought into my space was unparalleled.

In this post, I’ll share the essentials of creating your own iwagumi terrarium, drawing on my journey to help you bring a piece of tranquility into your home.

multiple small terrariums

What is an Iwagumi Style Terrarium?

The term Iwagumi is rooted in my fascination with the admirable simplicity and serene balance of Japanese aesthetics. It represents a specific style of aquascape that epitomizes the minimalist approach inherent in many Japanese art forms.

When I craft an Iwagumi terrarium, I’m not just arranging stones and plants; I’m creating a landscape that mirrors the Zen rock gardens found throughout Japan.

This aquascaping style hinges on the law of odd numbers, typically using an odd number of rocks to avoid symmetrical balance. The most significant stone, known as the oyaishi, serves as the focal point.

It is flanked by smaller, complementary stones, termed fukuishi, which support the main structure.

In a Sanzon Iwagumi, which I find especially compelling, the arrangement consists of three rocks, with the largest rock representing Buddha and the two smaller ones as his attendants.

I select flora that doesn’t overshadow the hardscape but enhances its natural beauty. I aim to create harmony between the rocks and plants, allowing the viewer’s eye to flow smoothly over the scape.

The main components of an Iwagumi terrarium include the rocks, the substrate, and the carefully chosen plants that complement the minimalist theme.

Iwagumi Terrarium Setup Principles

In setting up an Iwagumi terrarium, I adhere strictly to the principles of harmony and nature-inspired design. It’s all about careful placement and a keen eye for detail.

Simplicity and Minimalism

I embrace simplicity and minimalism in an Iwagumi terrarium. I use fewer elements to create a powerful visual impact, ensuring that each component has room to stand out. The focus is on clean lines and uncluttered space.

The Rule of Odd Numbers

I follow the rule of odd numbers when selecting rocks for my Iwagumi terrarium, as it’s believed to create a more natural and aesthetically pleasing arrangement. Typically, I choose three, five, or seven stones.

iwagumi aquascape layout rock positions with name
Iwagumi Aquascape Layout – Rock Positions & Their Names

Main Stone (Oyaishi)

The main stone, or Oyaishi, is my terrarium’s focal point. I select the largest and most impressive rock to serve as the Oyaishi, placing it slightly off-center to mimic natural landscapes.

See also  Iwagumi Layout Tutorial for Beginner Aquarists

Secondary Stones (Fukuishi and Soeishi)

For balance, I choose secondary stones, Fukuishi and Soeishi, ensuring they are smaller than the Oyaishi but still prominent. I position them in relation to the main stone to create a sense of flow and continuity.

Tertiary Stones (Suteishi)

Finally, I add the tertiary stones, Suteishi, which are the smallest and placed carefully to fill in the composition. I use these stones to enhance the overall layout and guide the eye through the terrarium.

terrarium inside glass bowl

What Materials You’ll Need To Setup An Iwagumi Terrarium?

When preparing to build my Iwagumi terrarium, I focus on simplicity and natural beauty. I gather specific materials to ensure my setup is authentic and thriving.

Terrarium Container

My choice of a terrarium container is crucial. I look for clear glass to allow unobstructed viewing and enough space to craft my miniature landscape.

A classic choice is a rectangular glass tank or round jar that’s at least 5 gallons, giving my layout depth while accommodating the rocks and plants.


Rocks are the centerpiece of an Iwagumi terrarium. The main stone, called the “Oyaishi,” should be the largest and most appealing. I’ll also need smaller rocks—“Fukuishi” and “Soeishi”—to complement it.

I choose rocks that resemble those in natural landscapes, often opting for types like Seiryu or Manten stone. They should create a harmonious, balanced look.

beautiful terrarium


The substrate, a mixture of soil and gravel, is pivotal for plant growth. I use plant soil, rich in nutrients, which promotes healthy roots. A thick layer at the base of my container will act as the foundation, sloping upward towards the back to create a sense of depth.


Choosing the right plants is vital for an Iwagumi terrarium. I select species that are low-growing and suitable for carpeting. They should be planted in small clumps throughout the substrate, allowing them to spread and form a natural-looking carpet.


  • Java Moss and Christmas Moss can adapt to terrestrial life if the humidity is kept high, but for a strictly terrestrial terrarium, consider these alternatives:
  • Sheet Moss (Hypnum sp.): Provides a lush, green carpet and thrives in humid, low-light conditions.
  • Mood Moss (Dicranum scoparium): Offers a slightly elevated, tufted appearance, adding texture to the terrarium floor.


  • Lemon Button Fern (Nephrolepis cordifolia ‘Duffii’): A small fern that’s perfect for terrariums due to its diminutive size and tolerance for high humidity.
  • Dwarf Japanese Holly Fern (Cyrtomium falcatum ‘Rochfordianum’): Offers a unique, dark green foliage that can complement the rocks in an iwagumi setup.

Ground Cover Plants

  • Corsican Mint (Mentha requienii): A tiny, fragrant ground cover that can thrive in the moist environment of a terrarium.
  • Irish Moss (Sagina subulata): Despite its name, it’s a flowering plant that forms a dense, moss-like carpet of bright green. It’s well-suited to the high humidity of a terrarium.

Small Terrestrial Carpeting Plants

  • Baby Tears (Soleirolia soleirolii): Not to be confused with Dwarf Baby Tears, this terrestrial plant forms a dense mat of tiny green leaves, ideal for creating a lush foreground.
  • Dwarf Hairgrass (Eleocharis parvula): Although often used in aquariums, it can adapt to very moist terrarium conditions, mimicking a mini grassland.


Lastly, I need several tools to set up my terrarium:

  • Tweezers for planting.
  • substrate spatula for shaping the landscape.
  • watering spray bottle for gentle water spraying without disrupting the layout.
  • Scissors for trimming plants as they grow.
See also  Can You Keep Betta Fish In Iwagumi Aquarium?

Having these materials on hand will help me construct a serene Iwagumi terrarium that’s both aesthetically pleasing and thriving.

Setting Up Your Iwagumi Terrarium

When I create an Iwagumi-style terrarium, my focus is on simplicity and natural beauty. This traditional Japanese aquascaping style brings peace and tranquility to a space, and careful preparation is key.

Planning Your Layout

First, I sketch out my layout, prioritizing balance and minimalism. Iwagumi relies on odd numbers of stones (mostly three), with the largest stone (the “Oyaishi”) as the focal point.

The other stones (the “Soeishi” and “Fukuishi”) complement this main stone, and together they form a natural-looking arrangement.

Preparing the Container

Choosing the right container sets the stage for my Iwagumi terrarium. A clear, low, and wide container without decorations enhances the view of the stones and plants.

I clean it with warm, soapy water and dry it completely to prevent any unwanted elements that could affect the plants.

Placing the Rocks

Rocks are the backbone of my Iwagumi terrarium. I place the Oyaishi first, slightly off-center, and angle it against the natural light source. Then, I add the secondary rocks, ensuring they point in the same direction to mimic natural water flow.

Adding Substrate

A proper substrate is crucial for plant growth. I prefer a nutrient-rich soil, poured evenly, but slightly deeper in the back for a layered look. It’s important to leave space around the stones to prevent debris accumulation.

Components of the Substrate Mix

Base Layer (Drainage Layer)

  • Expanded Clay Pebbles or Gravel: This layer at the bottom of the terrarium ensures excess water can drain away from the plant roots, preventing root rot. About a 1-inch layer is sufficient for most terrarium sizes.

Filter Layer

  • Mesh Screen: Placed on top of the drainage layer, a mesh screen (or landscape fabric) prevents the soil from mixing into the gravel, maintaining clear separation and effective drainage.

Main Substrate Layer

  • Peat Moss: Offers acidity and retains moisture well, beneficial for many terrarium plants.
  • Coco Coir: An eco-friendly peat alternative that helps in retaining moisture and providing a good structure for roots to grow.
  • Perlite or Vermiculite: Mixed in with peat moss or coco coir, these materials improve aeration and drainage within the soil.
  • Fine Sand: A small amount can help with drainage and stability, especially for anchoring rocks and plants.
  • Activated Charcoal (optional): A thin layer of activated charcoal above the drainage layer or mixed with the main substrate can help filter the air and water within the terrarium, keeping it fresh and reducing the growth of mold and bacteria.

Nutrient Layer (Optional)

  • Worm Castings: A small amount of worm castings can be added to the mix for a slow-release, organic nutrient source that will support plant growth without the risk of burning delicate roots.

Mixing and Layering the substrate

Layering: Begin by placing the drainage layer at the bottom of your terrarium. Cover it with a mesh screen to prevent soil from trickling down.

Substrate Mix Preparation: In a separate container, mix peat moss or coco coir with perlite or vermiculite at a ratio of about 3:1. You can add a small amount of fine sand to this mixture if desired. If using, sprinkle a thin layer of activated charcoal on the mesh screen before adding your main substrate mix.

Adding the Substrate: Pour the prepared substrate mix over the mesh screen, ensuring it’s deep enough to support plant roots but not so deep as to overwhelm the aesthetic of the rocks and plants. Typically, a depth of 2-3 inches is sufficient.

See also  What Types of Stones Are Used for Iwagumi Aquascape?

Nutrient Layer (Optional): If adding worm castings, mix them into the top inch of your substrate to avoid any potential mold growth on the surface.


Helanthium species are traditionally used in Iwagumi designs for their elegant appearance. I plant them carefully around the stones, keeping enough space for growth. I ensure the plants are secure and arrange them to mimic how they would naturally occur in the landscape.

Watering and Closing

Finally, I gently water the terrarium using a water spray bottle to prevent disturbing the substrate. The water level is just enough to moisten the soil without pooling. Then I cover the terrarium, allowing for some air circulation to keep my plants healthy.

unique style terrarium

How To Maintain Your Iwagumi Terrarium?

Maintaining an Iwagumi terrarium can be incredibly rewarding, provided I pay close attention to the essentials: lighting, watering, pruning, and pest management. Each element plays a vital part in keeping the terrarium healthy and thriving.


For my Iwagumi terrarium, proper lighting is absolutely critical. Plants in this style thrive under moderate to high lighting for about 8-10 hours daily. The goal is to mimic natural sunlight, balancing both intensity and duration.

I use LED lights because they offer a wide range of light spectrums suitable for terrarium plants and are energy-efficient.


Watering my Iwagumi terrarium isn’t just about the frequency but also about keeping water parameters stable. I aim to conduct partial water changes weekly, replacing around 20-25% of the water to remove waste and replenish nutrients.

It’s important to use dechlorinated water that’s at the same temperature as the tank to prevent shocking my plants and fish.

Trimming and Pruning

Regular trimming and pruning are critical for maintaining the minimalist aesthetic of my Iwagumi terrarium.

I trim the carpet plants to prevent them from overgrowing and overshadowing stones, and I’m careful not to disturb the layout while snipping away excess growth.

Pruning encourages denser growth, helping my plants stay healthy and in shape.

Dealing with Algae and Pests

Algae and pests can be a nuisance in any terrarium, and I tackle these issues head-on. For algae, I ensure nutrients and lighting are balanced and introduce algae-eating creatures if necessary.

When pests like snails or plant bugs appear, I manually remove them or use safe, targeted treatments to protect my terrarium’s ecosystem without harming the inhabitants.

Suitable Fauna For Iwagumi Terrarium

Incorporating fauna into an iwagumi terrarium introduces a dynamic element to the serene, minimalist landscape you’ve created, adding both movement and a unique aspect of care to your ecosystem.

However, it’s crucial to choose fauna that can thrive in the specific conditions of a terrarium while maintaining the aesthetic and ecological balance.

Here are some suitable options for fauna in an iwagumi terrarium:

  • Springtails (Collembola): These tiny detritivores are essential for a healthy terrarium ecosystem, helping to break down decaying plant matter and prevent mold growth. They are practically invisible and do not disturb the visual simplicity of the iwagumi style.
  • Isopods (Various species): Also known as pillbugs or woodlice, isopods come in various sizes and colors, including some visually interesting species like the dwarf white or powder blue isopods. They serve a similar ecological role to springtails, aiding in decomposition and soil aeration.

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Muntaseer Rahman

About Author

Hello, I’m Muntaseer Rahman, the owner of AcuarioPets.com. I’m passionate about aquarium pets like shrimps, snails, crabs, and crayfish. I’ve created this website to share my expertise and help you provide better care for these amazing pets.


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