Gardening 101: How to Make a Closed Terrarium by

Issue 95 · Southern Gothic · October 31, 2013

Gardening 101: How to Make a Closed Terrarium

Issue 95 · Southern Gothic · October 31, 2013

My first terrarium was an elaborate landscape, with little figurines holding hands on a park bench among the mossy plants. It convinced me heaven must be a velvety miniature world. But less than a week later: hell. Leaves shriveled, plants died, moss turned brittle. It was heartbreak for me—and for one tiny couple in love. This is how I learned you can't stick any old plants in some dirt in a jar and hope for the best. There's a right way to make a terrarium:

Photographs by John Merkl.

terrarium gardening 101 materials l Gardenista

Need to Know: There are two kinds of terrariums, open-sided containers and closed vessels. A terrarium with a lid will create a humid environment; make sure you choose plants that like moist soil and humid air. 

Keep it simple: All you need, in addition to a closed container, is pebbles, activated charcoal, potting soil, slow-growing small plants, and herb snips for shaping them.

terrarium gardening 101 drainage l Gardenista

Step 1: Spread a 1/2- to 1-inch layer of pebbles in the base of the container for drainage.

Step 2: Add a 1/2- to 1-inch layer of activated charcoal to filter the air in the closed environment. 

terrarium gardening 101 miniature plants l Gardenista

Step 3: Add a 1- to 2-inch deep layer of potting soil.

Step 4: Before planting, arrange plants—miniature ferns are a good choice in a closed environment—in the container with enough space to grow. Don't overcrowd. Trim leaves with herb snips, if necessary, to give plants room to breathe. 

Step 5: Hollow out a space in the potting soil for each plant. Firmly pat soil around the plants' roots. Water plants (but don't overwater—stop when the surface of the soil feels uniformly damp).

terrarium gardening 101 mist l Gardenista

Optional: Spray mist on plant leaves.

terrarium gardening 101 humidity l Gardenista

Step 6: Close container and place terrarium in a well-lit spot—but out of direct sunlight, because the glass will intensify the sun's rays. You don't want to fry the plants.

click here to see 10 terrariums l Gardenista

Little glasshouse terrariums with peaked roofs are called Wardian cases, named for the Victorian plant collector who invented them to transport specimens.

Are you a novice gardener? We have more Gardening 101 tips for you.



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