Why Do You Put Moss Under Soil in a Terrarium

Terrariums are miniature ecosystems that bring the beauty of nature indoors. They create a harmonious environment for plants to thrive and are visually stunning in their intricate designs. While setting up a terrarium, one of the crucial components is moss, particularly when it’s placed under the soil. If you’re new to terrariums, you may wonder why moss is used and how it benefits the ecosystem inside. This article will delve into the significance of placing moss under the soil in a terrarium and why it’s an essential step for maintaining a healthy environment for your plants.

What is a Terrarium?

A terrarium is a small, enclosed garden, usually housed in a transparent container like glass jars or bottles. It is an ideal option for indoor gardening as it allows you to grow a variety of plants in a controlled environment. There are two main types of terrariums: open and closed.

• Open Terrariums: These are exposed to the outside air, making them suitable for plants that thrive in dry environments, like succulents and cacti.
• Closed Terrariums: These are sealed, creating a humid environment perfect for moisture-loving plants like ferns, mosses, and tropical species.

Regardless of the type, terrariums are delicate ecosystems that need careful balancing of water, soil, and air circulation.

Role of Moss in a Terrarium

Moss, a small non-vascular plant, serves multiple purposes in a terrarium. While many people see moss purely for its aesthetic appeal, its function goes far beyond appearance. Moss acts as a key player in maintaining the balance of moisture, cleanliness, and structure within the terrarium.

• Water Retention: Moss has the remarkable ability to retain moisture, making it ideal for terrariums where high humidity is required. It absorbs excess water and slowly releases it back into the soil and air, preventing over-watering and maintaining a balanced environment.
• Filtration: When placed under the soil, moss acts as a filtration layer that prevents debris and contaminants from reaching the plant roots. It keeps the soil clean by trapping unwanted particles.
• Humidity Control: Moss helps regulate the humidity levels in closed terrariums. It stores moisture and releases it into the air when needed, keeping the environment conducive to plant growth.
• Structural Stability: Moss provides structural support to the soil, helping to stabilize it, especially in smaller containers. This can prevent soil erosion within the terrarium.

Why Put Moss Under Soil?

In terrarium setups, moss is often placed under the soil rather than on top. This strategic placement is not just about aesthetics; it serves critical functional roles that help the terrarium maintain its health and longevity.

a) Acts as a Drainage Layer

In a terrarium, having a proper drainage layer is essential to avoid waterlogging, which can lead to root rot. While many people use rocks, charcoal, or pebbles at the bottom of the terrarium for drainage, adding moss under the soil layer creates an additional buffer. Moss absorbs excess water, preventing the soil from becoming oversaturated.

This is especially important in closed terrariums, where water cannot evaporate as quickly as in open environments. By using moss as part of the drainage system, you’re creating a protective layer between the soil and water, keeping plant roots healthy.

b) Prevents Root Rot

Root rot is one of the most common issues in terrariums, especially in sealed environments where excess moisture can accumulate. When moss is placed under the soil, it acts as a moisture sponge, absorbing any extra water that might otherwise cause the roots to become waterlogged. Moss ensures that the soil remains well-drained, which minimizes the risk of root rot and helps plants thrive.

c) Enhances Soil Aeration

Plants need oxygen as much as they need water, and compacted soil can suffocate plant roots, causing them to fail. By placing moss under the soil, you improve the aeration of the root zone. Moss creates tiny air pockets, allowing oxygen to circulate more freely through the soil. This promotes healthier root development, ultimately leading to more robust plant growth.

d) Maintains a Clean Terrarium Environment

In terrariums, cleanliness is crucial for long-term plant health. Moss, when placed under the soil, acts as a filtration system, trapping dirt, particles, and impurities that might otherwise build up in the soil. This helps in preventing harmful bacteria or fungi from accumulating and affecting the plants’ health.

e) Provides Nutrients

As moss decomposes over time, it releases organic nutrients back into the soil. These nutrients are essential for plant growth, especially in a closed terrarium where the recycling of resources is vital. This decomposition process also mimics the natural ecosystem, ensuring a continuous supply of nutrients to the plants.

Types of Moss Used in Terrariums

There are several types of moss you can use in your terrarium, and each serves slightly different purposes. However, all can be placed under the soil to provide the same benefits discussed above.

• Sheet Moss (Hypnum moss): One of the most common moss types used in terrariums, sheet moss is versatile and can easily be placed under the soil. It’s excellent for absorbing moisture and adds aesthetic appeal.
• Sphagnum Moss: Known for its exceptional water retention capabilities, sphagnum moss is often used as a base layer in terrariums. Its sponge-like properties make it a popular choice for preventing root rot.
• Cushion Moss: This moss has a compact structure, making it ideal for smaller terrariums. Its ability to absorb and release water slowly is particularly useful in maintaining consistent moisture levels.
• Reindeer Moss: Although technically a lichen, reindeer moss is often used in terrariums for its unique appearance and moisture-retaining properties.

Step-by-Step Guide to Using Moss Under Soil in a Terrarium

Here is a simple guide on how to correctly place moss under the soil in your terrarium:

Step 1: Prepare the Container

Choose a suitable container for your terrarium. For closed terrariums, glass containers with lids work well, while open terrariums are ideal for dry-loving plants.

Step 2: Add the Drainage Layer

Add a layer of small stones, pebbles, or activated charcoal at the bottom of the terrarium. This acts as the primary drainage system.

Step 3: Place Moss Over the Drainage Layer

Once the drainage layer is set, place a layer of moss over it. Ensure the moss is evenly spread to cover the entire surface. This will act as an intermediary layer, helping with water absorption and preventing soil from sinking into the drainage system.

Step 4: Add Soil

On top of the moss layer, add your soil. Depending on the plants you’re using, select a soil mixture that supports their specific needs. Ensure the soil is loose and well-drained.

Step 5: Plant Your Plants

Once the soil is in place, you can begin planting your plants. Make sure the roots are properly embedded in the soil and not directly in contact with the moss layer.

Step 6: Finish with Decorations (Optional)

If desired, add decorative elements like stones, figurines, or more moss on the surface to enhance the visual appeal of the terrarium.

Benefits of Using Moss in a Terrarium

Moss is more than just an aesthetic element in a terrarium. Its ability to retain moisture, regulate humidity, and improve soil health makes it indispensable. Here are some of the key benefits of using moss in your terrarium:

• Natural Water Cycle: Moss helps create a natural water cycle within the terrarium, ensuring that plants receive just the right amount of moisture.
• Improved Root Health: By preventing over-watering and promoting soil aeration, moss encourages strong, healthy root development.
• Longer-Lasting Terrariums: Moss helps maintain the terrarium environment over the long term, reducing the need for frequent maintenance.

Conclusion

Incorporating moss under the soil in a terrarium offers numerous benefits, from enhancing drainage and preventing root rot to promoting soil aeration and nutrient cycling. It plays a critical role in maintaining a balanced ecosystem within the enclosed environment, allowing your plants to thrive. So, the next time you set up a terrarium, remember to include moss in your layering strategy—it’s a small addition that can make a world of difference.