Terrarium Basics

WHAT IS A TERRARIUM?

Terrariums galore

Terrariums are living plants housed in clear containers. They are decorative and designed to complement and enhance living spaces, giving them a touch of nature in a capsule, like a portal to a forest. They are miniature gardens and a simple entry point to discovering plants.

TYPES OF TERRARIUMS

There are broadly 2 major types of terrariums – closed and open. Plants have specific needs and are best paired with a right type of terrarium.

Closed terrariums go with ‘wet’ plants that prefer high humidity. Examples would be moss, rainforest plants such as ferns, and aquatic plants. When a lid is left on, water is trapped inside the terrarium and humidity increases, so closed terrariums hardly require watering. With sufficient light, moisture loving plants can live off the contained air and water for long periods, making closed terrariums one of the easiest to maintain.

Open terrariums go with ‘dry’ plants, those that prefer good air circulation and dislike prolonged exposure to moisture. Examples would be succulents, cacti and air plants. Open terrariums allow air to circulate and moisture to evaporate. They are not too different from a planted pot with a little extra decoration.

PAIRING PLANTS WITH TERRARIUMS

Another way to look at terrariums is to consider the needs of the plant and working backwards to identify the right terrarium for them. Plants originate from various parts of the natural world, from deserts to rainforests to wet swamps. In the wild they experience different conditions for light, humidity and temperature. The fundamental goal of plant care is to simulate these natural conditions to keep plants thriving in our homes. There are an endless variety of plants that work as tabletop decor, here we cover a few common types.

Moss

Mosses love moisture and can survive under moderate to strong light provided sufficiently wet and cool. They do not possess proper roots so do not need soil to grow and can be found on stone, concrete and tree bark. They absorb water and nutrients through their thin skin like a sponge. Also like a sponge, they lose water very easily so their survival depends on constant humidity. Moss is one of the easiest plants for closed terrariums and can tolerate most indoor lighting situations.

Succulents

Succulents and cacti are plants that have adapted to arid desert-like conditions. They do best under sunlight and can retain water to survive droughts. They require infrequent watering, good air flow and gritty, fast draining soil. Prolonged moisture exposure can damage them, especially portions closest to wet soil. They are best in open terrariums made with fast draining soil and placed in a bright breezy spot, say on a patio table or next to a window. If kept indoors they will benefit from frequent sunbathing outdoors.

Xerographica air plant

Air plants have no need for soil, making them a great option for plant styling. In the wild they attach themselves to trees, rocks and shrubs preferring bright breezy places with good air flow . They enjoy a good watering but need to dry completely within a few hours or will get moisture damaged. Air plants are best in open terrariums placed in bright, non-direct sunlight with good circulation, although certain exceptional species can survive in closed jars.

Aquatic plants grown on a wabi-kusa ball

Aquatic plants are plants that can be found submerged underwater or emersed above water in very humid conditions. In the wild they come from fresh water rivers and lakes with periods of being submerged and being above water depending on rainfall. Aquatic plants can be kept in closed terrariums that provide high humidity. Lighting requirements vary among aquatic plants depending on where they naturally grow, some take direct sunlight while others prefer less intense light.

Various small herbaceous plants
Herbaceous plants are soft-bodied evergreen plants, many small ones are commonly used for terrariums. Examples include ferns, selaginella, fittonia, peperomia, alternanthera, ficus pumila, bromeliads and carnivorous plants. They could do well in either a closed or open terrarium or both depending on their preference for humidity and air flow. Most ornamental herbaceous plants fare better with non-direct sunlight next to a window or a patio table in a balcony.
Bonsai kokedama

Bonsai is the Japanese craft of miniaturizing a tree or shrub by stunting its growth through some form of physical intervention, most commonly wrapping wires around young branches before they harden. Some bonsai are small enough to fit inside a terrarium but whether open or closed depends on the nature of the tree. For example a water jasmine bonsai likes humidity and could be placed in a closed terrarium. Most bonsai require strong sunlight to grow full and luscious leaves.

And that’s terrarium basics, now you know!