A terrarium is a beautiful miniature landscape with a climate of its own, like a tiny greenhouse! Terrariums encapsulate the beauty and balance of nature by simulating a small-scale ecosystem in a glass container.
Along with being fun to create and easy to maintain, terrariums make great home décor and lovely gifts for friends and family. They are also the perfect Earth Day activity! There are just a few guidelines to follow for a long-lasting, living masterpiece—read on for our step-by-step process and tips on how to create your own custom terrarium.
The Best Plants to Use for Terrariums
Choose your terrarium plants based on the light exposure of your space as well as the type of container you want to use. If you plan to keep it in a bright, sunny windowsill, it’s best to select the appropriate plants for sun and avoid certain container shapes. If you plan to keep your terrarium in a dimly lit room or well away from windows, a different selection of plants will thrive and certain containers will work better than others.
Plants for Sun Terrariums
- Bromeliads & Epiphytes
- Cacti & Succulents
- Nerve Plant
- Peperomia
- Pilea
- Polka Dot Plant
Plants for Shade Terrariums
Unlike a terrarium, an aerium is made without the use of soil to display Tillandsias, or air plants!
Choosing a Terrarium Container
It’s best to use a clear, glass container for your terrarium. The container can be tall or short, and open or closed with a lid.
Just keep in mind that the size of the opening will influence the amount of airflow inside the container—a narrow opening will stay moist (better for mosses and tropicals), whereas a wide-mouthed jar will dry out more quickly (great for cacti and succulents).
Open terrariums need more consistent moisture and watering, while terrariums in closed containers require less maintenance.
The airspace or headroom above the plants inside a container should ideally be at least half of the container’s volume or more.
The 7 Layers of a Terrarium
1. Rocks, Stones, or Pebbles: Layer the bottom of your container with rocks, stones, or pebbles.
2. Horticultural Charcoal: Sprinkle on top of first layer; charcoal helps filter air and water and prevents the terrarium environment from succumbing to moisture-loving bacteria.
3. Sphagnum Moss: This dried moss helps retain moisture and acts as a filter between the soil and rock layers, plus it adds attractive texture!
4. Bonsai Soil Mix: This indoor potting mix is the perfect blend of organic matter; includes more sand and pumice than most potting soils to encourage drainage without drying out too quickly.
5. Plants: Less is more—be careful not to crowd your container with too many plants.
6. Top Dressing: Top dress your terrarium with smaller, neutral-colored stones and accent with larger rocks or more colorful stones for a fun contrast.
7. Personality: Customize your creation with something that makes you smile, such as gemstones, a feather you found on a hike, or a miniature figurine to add a bit of whimsy!
Helpful Tools for Creating a Terrarium
- Long tweezers make it much easier to work in the tight spaces of your glass vessel (and are extra useful when handeling Cacti)
- Gloves help protect your hands from sharp Cacti spines (you can also use a sponge)
- Small scoop, funnel, or spoon to pour and place materials into small spaces
- Small brush to dust off wayward bits
- Spray bottle to clean glassware and water your finished creation
How to Maintain a Terrarium
Balancing light and moisture for your plants’ needs is key to a healthy terrarium. Shade plants will need less water than sun-loving plants, while mosses and ferns prefer more constant moisture. Most closed terrariums will be happy with a misting every one or two weeks, where succulents or dry plantings should only be watered lightly every two weeks or so.
If your open terrarium seems to be drying out, but you can see water in the bottom rock layer, try covering with cling-wrap or closing your container for a day or two to redistribute the moisture. This works well for newly planted projects that have yet to fully develop new roots.