5 Key Succulent Terrarium Layers and Planting Ideas

Creating a succulent terrarium can be rewarding. It is a great way of displaying various succulent varieties in your indoor garden. However, if not designed well, terrariums can become excessively humid, leading to overwatering and mold issues that can kill the plant.

You can create suitable growth conditions for succulents in a terrarium by layering various materials that aid in drainage, airflow, and proper establishment of the plants. In this guide. I’ll explain 5 important terrarium layers that are essential when growing succulents.

Important succulent terrarium layers

Terrariums are made from containers without drainage holes. This can be a risk to succulents and other water-sensitive plants. Here are the important layers needed in a succulent terrarium. 

Drainage layer 

Succulents prefer well-draining soil to thrive. Planting succulents in a container without drainage can cause root rot and other fungal problems. Excess water in the soil deprives roots of oxygen causing them to die and rot. This problem can also be caused by overwatering the plants.

When creating a succulent terrarium, start with a layer of pebbles or small rocks at the bottom of the jar. This is the most important layer that helps with drainage. Basically, this is where excess water from the soil collects. The depth of this layer can range from an inch to two depending on the size of the terrarium.

The gaps in the rocky material of the drainage layer also promote air circulation in the root zone. This promotes healthier root growth and reduced chances of root rot and other fungal infections. However, less watering is key in controlling the amount of water that collects in the drainage layer.

Activated Charcoal 

Some terrariums include a thin layer of activated charcoal on top of the rock layer. Charcoal helps to filter and purify the air within the terrarium. This helps in preventing any odors or potential bacterial growth. This layer is important in the maintenance of closed terrariums.

Activated charcoal is a highly porous form of carbon. It is formulated by heating charcoal at extremely high temperatures to increase its porosity. Activated charcoal can absorb odors, toxins, and other impurities. It is commonly used in water and air purification processes.

Including activated carbon in a succulent terrarium is not essential but can be beneficial to your plants. 

Mesh or screen 

A fine mesh can be placed on top of the drainage layer or the activated charcoal layer to create a barrier between the rocks and the potting soil. This prevents the soil from sinking into the drainage layer while still allowing the water to pass through.

In terrariums where sphagnum moss is used, the mesh can be placed over the moss layer to hold it in place and prevent it from mixing with the soil. Sphagnum moss is good at retaining and is not recommended for use when creating cacti and succulent terrariums.

Potting mix layer 

The next essential terrarium layer is the potting mix. As said succulents need soil that drains sharply. So, this layer should consist of a well-draining succulent or cactus potting mix. You can buy the potting mix or create your own by combining regular potting soil with pumice or perlite to improve drainage. 

This layer must also provide succulents with the necessary nutrients and support for their root development. A small percentage of well-decomposed compost or coconut coir can be added to the mix to provide some nutrients and improve moisture retention.

Decorative layer

For an extra touch, you can add a layer of decorative topdressing on top of the potting mix. You can use small pebbles, colorful stones, or crushed shells to create a coastal theme. Some people would add small pieces of live or preserved moss and lichen to mimic forest conditions.

This layer not only enhances the terrarium’s aesthetics but also helps to retain moisture. But remember, moderation is key when adding decorative elements to a terrarium. You don’t want to overcrowd the space, as it might affect plant growth or create a cluttered appearance.

Note: Creating a succulent terrarium might require purchasing various items that include suitable plants, mesh, potting mix, decorative elements, and the terrarium container itself. So be ready to set aside a budget for all the important requirements.

Planting succulents in a terrarium

Succulents are best grown in open terrariums which allow free air flow around the plants. This can greatly reduce the chances of overwatering and humidity buildup in the container. As you know, most succulents thrive in dry conditions and they don’t like when there is excess moisture around them.

For easy maintenance of your terrarium, choose succulents with similar care needs if you are planting more than one variety. Avoid succulents that grow too fast and extremely big as they can outgrow the terrarium in just a short period of time.

When planting, arrange them according to your design preferences but leave some space between each plant to allow for growth. I love planting taller succulents at the far end of the display. Fake plants and other animal decorations can also be added to create a more appealing look.

Care and maintenance

If your terrarium has a lid or cover, adjust the watering frequency to prevent root rot and other fungal issues. Just mist the plants when it’s time to water. Additionally, open the lid periodically to release excess moisture and allow fresh air circulation.

Light is essential for terrarium succulents as it enables plants to carry out photosynthesis. Make sure your plants are receiving the right amount of sunlight. Insufficient lighting may cause the plants to grow thin and spindly or even die due to lack of sugars.

Monitoring the terrarium plants regularly is highly recommended. Prune plants that have become too large for the terrarium or repot them in a big container if they have completely outgrown the space. This problem can be prevented by opting for smaller plant types.

Final thought

Terrariums are great at displaying plants in a unique way. If you are interested in creating a succulent terrarium, include all the important layers. Additionally, choose plants that befit your terrarium growth conditions and provide adequate care.