Learn How to Make a Terrarium at Home

Understanding What a Terrarium Is and Why People Create Them

A terrarium is a enclosed glass or clear plastic container that holds soil, plants, and sometimes rocks and decorative elements. The container creates a miniature ecosystem where plants can grow in a controlled environment. The word "terrarium" comes from Latin—"terra" meaning earth and "arium" meaning place or container. People have been creating terrariums since the Victorian era in the 1800s, when they became popular in Europe as decorative indoor gardens.

Terrariums work through a natural water cycle. When you water the plants inside a sealed or semi-sealed container, the soil absorbs moisture. Plants then release water vapor through their leaves in a process called transpiration. This vapor rises, condenses on the glass or plastic walls, and drips back down to the soil. This cycle reduces how often you need to water compared to regular potted plants. The enclosed environment also protects delicate plants from drafts and fluctuating humidity levels.

People create terrariums for several reasons. They make attractive decorations for desks, shelves, and tables. They take up minimal space, making them ideal for apartments or small homes. Terrariums also offer an educational opportunity to observe how plants grow and how ecosystems function. Some people find the process of building and maintaining a terrarium calming and meditative. Terrariums can cost anywhere from $20 to $100 depending on the container size and materials you choose.

Practical Takeaway: Before starting your terrarium, think about where you want to place it and what size makes sense for that space. A small desktop terrarium differs greatly from a large floor-standing one. Understanding the basic water cycle will help you avoid common mistakes like overwatering.

Selecting the Right Container and Materials

The container is the foundation of your terrarium. Glass containers work best because they allow light to enter and let you observe the plants inside. Common container options include clear glass bowls, jars with lids, old aquariums, geometric glass terrariums, or even wine bottles and test tubes for small terrariums. The size should match your space and plant choices—a container that is too large becomes difficult to maintain, while one that is too small restricts plant growth.

When choosing a container, consider whether you want an open or closed terrarium. A closed terrarium has a lid or seal, creating a humid environment where moisture cycles continuously. These work well for tropical plants and ferns that love humidity. An open terrarium has no lid, allowing more air circulation. Open terrariums suit succulents and cacti that prefer drier conditions. Many people start with open terrariums because they are simpler to maintain and harder to accidentally overwater.

Container material matters for durability and visibility. Glass is the most popular choice because it doesn't degrade and provides clear views from all angles. Plastic containers are lighter and cheaper but may become cloudy over time and are more prone to scratches. Some people repurpose household items—mason jars, old fish tanks, decorative bottles, or food storage containers can all work. Just ensure the container is clean before use. If using a previously used container, wash it with hot water and let it dry completely.

The container should have an opening large enough to insert plants and materials. Some terrarium enthusiasts buy containers with removable lids so they can access the interior easily. If you use a narrow-necked bottle, you may need to create tools from chopsticks or rolled paper to help position plants inside. Drainage holes are not necessary in a terrarium because the closed environment controls moisture, but if your container has holes, you can still use it—just be more cautious with watering.

Practical Takeaway: Visit a craft store or home goods retailer to examine containers in person. Hold them up to the light to check clarity. Test the opening size by inserting your hand or a small object to confirm you can maneuver plants inside. A 5-to-10-gallon glass container makes a good starting size for beginners.

Gathering Substrate and Layering Materials

Substrate is the foundation layer inside your terrarium. It typically consists of several distinct layers that work together to support plant health and manage water drainage. Understanding each layer helps you create an environment where plants thrive and moisture stays balanced.

The first layer at the bottom should be drainage material. This prevents water from pooling directly under the roots. Common drainage materials include pebbles, gravel, or small rocks. Use stones about the size of a pea to a marble. Spread this layer about 1 to 2 inches thick across the bottom of the container. This layer is especially important in closed terrariums where water cannot evaporate as quickly. Some terrarium builders add activated charcoal on top of the drainage layer. Activated charcoal is a porous material that filters water and prevents mold and unpleasant odors from developing in closed containers. You can find activated charcoal at garden centers, pet stores, or online retailers for approximately $5 to $10 per bag.

The next layer is soil or growing medium. The type of soil depends on the plants you select. For tropical plants and ferns, use potting soil mixed with sphagnum moss or peat moss to retain moisture. For succulents and cacti, use cactus or succulent soil that drains quickly. Avoid using garden soil from your yard—it contains bacteria, insects, and may be too dense for container growing. Purchase bagged potting soil from any garden center or home improvement store. Spread this soil layer 2 to 3 inches thick over the charcoal. Moisten the soil slightly before adding it so it compacts better and settles properly.

Some terrarium builders add a moss layer between the charcoal and soil. Sphagnum moss or sheet moss acts as a barrier that prevents soil from falling into the drainage layer while still allowing water to flow through. This layer is optional but can extend the life of your drainage materials by keeping them cleaner. If you include a moss layer, make it about 0.5 to 1 inch thick.

Practical Takeaway: Gather all materials before you begin assembly. Prepare your layers in containers nearby so you can add them in order without stopping to search for items. The total depth of drainage, charcoal, moss, and soil should be about 4 to 6 inches for most terrariums, leaving room for plants and decorative elements above.

Choosing and Planting Vegetation

Plant selection determines whether your terrarium will thrive or struggle. The key is choosing plants that share similar light and humidity requirements. Mixing plants with very different needs—like a cactus with a fern—often leads to one plant declining while the other flourishes. Most terrarium plants are small, slow-growing varieties that remain compact in enclosed spaces.

For closed, humid terrariums, consider tropical and shade-loving plants. Ferns such as maidenhair fern, button fern, and brake fern work well. Peperomia is a small plant with attractive leaves and minimal water needs. Pothos or devil's ivy grows slowly in low light. Calathea and maranta (prayer plants) have beautiful patterned leaves. African violets produce delicate flowers and thrive in humidity. Begonias offer variety in leaf color and texture. Mosses, including sheet moss and mood moss, add texture and moisture retention. These plants typically cost $3 to $8 each at garden centers or nurseries.

For open, drier terrariums, succulents are ideal. Echeveria, jade plants, aloe vera, and haworthia are hardy succulents that store water in their leaves. Sedums come in numerous varieties with different colors and growth patterns. String of pearls (senecio) creates trailing interest. Jade plants have thick leaves and tree-like growth. Air plants (tillandsia) require no soil and attach to rocks or wood. Cacti offer sculptural interest and extreme drought tolerance. Succulents generally cost $2 to $6 each.

When planting, start with the largest plants first, positioning them toward the back or center depending on your design. Leave space around each plant for growth. Remove plants from their original pots and gently loosen the roots with your fingers. Create small holes in the soil and nestle the roots in gently. Pat soil around the base to secure the plant. Add smaller plants and filler plants around the larger specimens. For a finished look, arrange plants at varying heights rather than