LAYER ONE: DRAINAGE
This layer is also called a false bottom or water reservoir. It prevents plant roots from sitting in water, which can lead to rotting. Water percolates down into this layer until it can evaporate.
Drainage Mediums
• pebbles
• sand
• gravel
LAYER TWO: SEPARATION
This layer is optional but effective! It prevents the soil layer from falling into the drainage layer. This can get messy and take away from the overall appearance. Dried sphagnum moss is a popular choice for this layer. Before placing dried sphagnum moss into any terrarium project, first soak the moss in water for 10 minutes and then squeeze and drain out the excess water and let the moss dry. My favorite medium to use for this layer is fiberglass mesh. Hardware stores sell this mesh in rolls and the tiny holes in the screen allow water to easily pass through but deter the soil from falling through to the bottom. (Turn to the next page to see how to prepare it.)
Separation Mediums
• dried sphagnum moss
• butcher paper
• fiberglass screen sheet (window or fly screen)
HOW TO CUT FIBERGLASS MESH
Place your container on the screen. Use a marker to trace around the container and cut the screen.
If you don’t want the screen to show as prominently through the glass, you can cut it slightly smaller than the size of the container.
LAYER THREE: FILTRATION
This layer is used to filter the water that will come down through the substrate layer. Horticultural charcoal will help keep mold from growing inside the terrarium. It will also keep the terrarium smelling fresh and do away with that mildew-like scent that can sometimes accompany damp areas.
Filtration Medium
• horticultural charcoal
LAYER FOUR: SUBSTRATE
This layer is for the soil. The type of soil medium depends on the type of plants used. Some tropical plants prefer more acidic soil than others. We’ll talk more about the most suitable soil for your plants in the foundation section (see here). This substrate layer should be similar in depth to your drainage layer. Soil can become very saturated with water before it begins to percolate to the bottom. If the water reservoir is too shallow it will flood, and the roots of your plants will stay wet. This can lead to root rot and unfortunately kill your plants.
Substrate Mediums
• potting soil
• succulents and cacti soil mix
• peat moss soil mix
• orchid soil mix
LAYER FIVE: PLANTS
After you have layered the foundation of the terrarium it’s time to add your plants. The types of plants you use depend on the type of vessel. Remove plants from their pots, clean away any excess soil from the roots, and place them directly in the soil. Then cover the roots with soil, and pat down firmly.
Closed Terrarium Plants
• ferns
• mosses
• tropical plants
Open Terrarium Plants
• tillandsias (air plants)
• cacti
• succulents
LAYER SIX: TOPDRESSING
This layer is purely decorative. You can cover the substrate layer with a more attractive topper. Use a bamboo skewer or wood dowel to spread the medium between plants and cover the soil completely.
Topdressing Mediums
• sand
• pebbles
• crushed glass
• crushed seashells
LAYER SEVEN: DECORATIVE ELEMENTS
Decorative elements are not always necessary but they can add character to a themed terrarium!
Decorative Mediums
• seashells
• figurines
• crystals
• rocks
• sea fans
• reindeer moss
VESSELS
LOCATION, LOCATION, LOCATION
Traditionally, when we think of terrariums, we picture thick green foliage in a sealed glass vessel. But let’s face it: there are so many more options for displaying plants these days that it’s worth breaking the mold. Before deciding on an appropriate vessel for your terrarium, you’ll want to ask yourself a few questions: Where will the terrarium live? On a nightstand, so it’s the first thing you see in the morning? On a coffee table, for all to see? Are you all out of counter space? Then how about suspended from a wall or ceiling? Once you have the location all figured out, think about what type of vessel would work best in that space. A vessel with a flat bottom works best on a shelf, a vessel offering unobstructed 360-degree views is the perfect centerpiece for a coffee table, and a vessel with a hook is perfect for stringing up anywhere around your home.