Terrariums are easy to care for miniature gardens enclosed in glass. Their humid environment is ideal for growing tropical plants that don't normally thrive indoors. This segment demonstrates the basic steps for designing a terrarium.

Produced by the Department of Communications at Kansas State University. For more information, visit our website at: http://www.kansasgreenyards.org


Terrariums are a good way to bring your outside environment to your inside environment. Here, we have the simplest kind. It’s just a plant with a cloche over it. This increases the humidity, and it makes a very pretty display. I’ve seen a lot of these with orchids, and they’re very nice. You don’t need any type of fancy jar. Basically, any glass container can be a terrarium.

The first thing you’ll need is pea gravel. Just add about an inch to give drainage to the plant, so it doesn’t get too wet. Then, on top of that you’ll need about 1/2 inch of activated charcoal that you can buy at an aquarium store, or a pet store. This will help keep it fresh, so that it doesn’t smell. The next step is to add media – this is just store-bought media. Just add that in until it covers 1/4 to 1/3 of the jar, including the gravel and activated charcoal. Just take your hand and pat it down to push out any air. Then, we’re ready to add our plants.

When you’re choosing your plants, you’ll need plants that have similar light and soil requirements. You’ll also want plants that can withstand high humidity. Not everything will work. For instance, tropical and cactus plants would not mix well. We want the roots to spread everywhere, but this one is root bound. And we can’t shake any of the dirt off, so we’ll have to cut it. Make an incision about halfway up to the top, and now you can get the roots to spread better.

Make a little hole for it, and get all the tendrils going the right way. Then, make sure all the roots are covered up. Bromeliads are usually known for their small root systems, so we’ll be able to knock most of the soil from this one. I’ll make a small hole for it to go in, and then, I’ll put that in there. And finally, we have this taller plant. It’s a woody species I chose because it’s going to be easier to trim to keep it in the jar. Just pull it out. This one also has a fibrous root system, but not nearly as bad as our creeping plant. I’ll knock some of the soil off. Since I can’t get most of the soil off, I’ll have to cut this one, too. Just cut, and split, and then dig the hole. There, that should be enough room. The last part of the terrarium is the fun part.

You can put all sorts of decorations in your terrarium. You could to where they sell bonsai equipment. They’ll usually sell small figurines such as little gnomes, or any kitschy item you want. I’m just going to put some plain old rocks in, because I want this to look more like a natural scene. I’m just going to put them in randomly to add some contrast in color.

You don’t need to water it right now. Sometimes during the summer, they might need a little bit more water, and during the winter, they might need it a little less. But, usually, a terrarium will need water every two to three months. The best way to check to see if you need to water is to look at the soil. It will change to a different color. Or, you can take your finger and feel to see if the soil is wet. If you overwater your plant, you’ll see that the gravel has a lot of water in it. If that happens, you’ll need to keep the lid off and let it dry out.

Also, you should not use fertilizer. You’ll want your plants to stay in the terrarium. If you over fertilize them, they’ll grow too large, and you won’t be able to keep all the plants in. But, if they look like need fertilizer – if the leaves are starting to turn yellow, or you see some signs of nutrient deficiency, you should give the plant just 5 to 10 percent of the recommended rate listed on the fertilizer package. The solution should be very dilute.

Where you place the terrarium is also very important. Find a spot away from the window with indirect sunlight. You’ll want it to be warm, but not near a heating vent. If any of the plants are dying from a mold or fungus problem, you’ll need to immediately take the diseased plant out. Isolate the diseased plant by placing it in a rag and discard in another room. You’ll need to keep the terrarium as clean as possible.

This feature story prepared with Zachariah Starr, former Kansas State University Horticulture Graduate Student. For more information, visit your local county extension office or visit our website at KansasGreenYards.org.

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