Ingredients for a Successful Terrarium Garden

It's best to assemble the tools, supplies and plants you'll need before starting your project. You will need:

  • A large glass container, one gallon or larger, with an opening wide enough to accommodate your hand so that you can place plants and tend your garden. Suitable containers can be purchased online or from the house wares section at your local store, where they are sold as canisters for flour, sugar and other dried goods. The containers should have a lid of some type. The container must be tall enough to accommodate growing plants.
  • Sterile potting soil.
  • Activated charcoal, such as the kind used for aquarium filters.
  • Pebbles
  • Miniature plants suitable for the environment where you will place your terrarium.
  • Moss, rocks and ornaments to decorate the terrarium.

Plants for Terrariums

Many garden centers stock small house plants suitable for terrariums. When choosing plants for your container garden, choose plants with similar water, light and soil requirements. Consider where you plan to keep your terrarium; what kind of light does the area receive? If it's a low light area, then choose plants accordingly, for example.

Another consideration is foliage color and texture. Because several plants will be grouped together, choose plants with different colors and textures.
Lastly, make sure you choose dwarf plants. Read the plant label to make sure the plant you're choosing won't outgrow its environment.

Some plants for terrariums include:

Build Your Container Garden

To plant a terrarium or container garden, start by thoroughly cleaning and drying the container. Remove any labels.

Place a half inch of activated charcoal and pebbles on the bottom of the container. Activated charcoal absorbs odors and pebbles improve drainage to prevent water from collecting near the plants' roots.

Add soil on top of the charcoal and pebble mixture. You'll need approximately two inches or more of soil, depending on the height of the container. You can smooth it flat or, to add interest, create a little shelf for smaller plants by terracing the soil.

Before permanently placing your plants in container, you may want to place them loosely in the soil to see how you like the arrangement of textures and colors. Move them around until you like the arrangement, then use a stick or a spoon to dig a little hole for the roots. Plant your selections and gently tamp down the soil around the plants.

Now add the moss around the plants to cover the soil. Add ornaments such as rocks, fish tank ornaments and figures, small pieces of driftwood and the like to finish your garden.

Water the terrarium using a spray bottle or mister. Close the top, and place the terrarium near an appropriate light source such as on a windowsill or a table near a window. Never place your terrarium in direct sunlight such as a south-facing window. The sealed environment "cooks" the plants and it can rapidly overheat.

Care of the Terrarium Garden

For the first week or two, leave the top off the container to allow free air circulation. Water the mosses and plants using a mister or spray bottle. Remove any dead leaves or flowers promptly. After the first few weeks, replace the cap and reduce watering to a simple squirt once a week. Too much water isn't good for plants. Because the terrarium garden doesn't have any external drainage holes, water that collects on the bottom of the terrarium may cause plants to rot. Water less, rather than more, if you're not sure of how much water to give your terrarium plants.

Terrarium gardens can last for many years, but at some point, plants may grow too large for the container, or plants may die. Simply remove big plants and transplant them to a separate container. Remove dead plants and replace with new ones to refresh your terrarium.