Today we are going to be making a terrarium. “Terra” is the Latin word for earth or ground. A terrarium is simply a representation of a land environment. There are a large number of small plants that are well-suited to being grown in terrariums. Typically plants that have small leaves and are slow growers will perform best. Terrariums can replicate desert environments using sand as the growing medium and planted with succulent or cacti. They can also replicate woodland environments and feature moss, lichens, and other small plants.
To assemble your terrarium, start off with a glass container. It can be something as small as a mason jar or as big as an aquarium. You can grow an open or closed terrarium. Closed terrariums, once established, can go for weeks or months without much care. Open terrariums usually need to be misted or watered periodically.
Next, add a layer of gravel to the bottom of the terrarium. This will let the soil drain, and it will also act as a reservoir. This layer should be one-half to two inches in depth depending on the size of the container you choose.
On top of the gravel add a layer of potting mix. Be careful to use a sterile mix that is seed free. A weed sprouting in a small terrarium can become a big problem. Most bagged potting mixes should be fine. The potting mix should fill the container one third of the way.
If you are assembling a large terrarium, you will want to add your plants next. Plants like ivy, hypoestes, and African violets work great. Then plant moss over the remaining area. For a small terrarium, moss is usually all that will fit.
Generally, if a terrarium is small, only simple, less complex organisms, like moss, will thrive. This is because you are basically creating a closed ecosystem where the organisms are competing with each other for survival. The “carrying capacity” of the artificial habitat comes into play.
Finish up your terrarium with decorative rocks, gravel paths, tiny gnomes, and other items to create your own miniature world. To add a little more life try adding sticks with lichens on them. Did you know that lichens are symbiotic organisms? They are made up of algae and fungi species living together as one.
Terrariums are very easy to care for. Place your terrarium in an area where it gets plenty of light, but never direct sunlight. They are essentially a miniature greenhouse so direct sunlight can cook the contents.
Monitor your terrarium during the first week to ten days. If it seems like there is too much moisture inside, open the lid slightly to let it dry out a bit. Some condensation on the glass is normal, but too much moisture can kill your plants. Once established, terrariums can grow unattended for weeks at a time.
Terrariums make a great project for beginning gardeners, adults and kids alike. For children, they are a great way to tech scientific concepts like ecosystems, biomes, and about the water cycle. They also make stylish focal points for rooms, bringing a little bit of green indoors during grey winter days.