I love stepping into my greenhouse on a cold winter day. The world around the greenhouse is cold, but in my little greenhouse the temperatures are warm enough to grow amaryllis, geraniums and succulents.
A miniature version of a greenhouse that anyone with an indoor space can grow is a terrarium. A terrarium is a self-contained microclimate where plants can grow. Terrariums can be as simple as a single flower growing in or under glass or as complex as a miniature garden with accessories that create a scene.
Terrariums as we know them today were discovered by British scientists that found that plants flourished indoors, under glass when the factory fumes outside would kill the same plants.
Today, terrariums range from woodland themes with moss, lichen and ferns to carnivorous bogs with Venus flytraps and pitcher plants. A terrarium will thrive in a dry, indoor atmosphere because of the humidity control created by the glass housing the plants. Plants absorb water from the soil and release it from their leaves back into the atmosphere where it collects on the glass and drips back into the soil to be absorbed by the plant.
Any clear or almost clear glass container will make a nice terrarium. Choose a container with an opening large enough to get your hand into. A lid or top is fine but not absolutely necessary. A completely closed terrarium will promote mold growth, so you should leave a small gap at the top of the terrarium for air.
Place one to two inches of pea gravel or pebbles in the terrarium bottom for drainage. Sprinkle a thin layer of activated charcoal on top of the base. Next, add a slightly moist but well-draining potting soil. The soil should be at least one and a half inches deep up to a quarter of the terrarium’s height.
Choose plants for the terrarium that don’t grow too large or grow too quickly. Moss, bromeliads, fuchsias, begonias, ferns and philodendrons are all plants that will do well in a terrarium environment. Plants should also complement each other. For example, a light loving begonia should not be paired with an indirect light preferring plant like a fern.
Use a long spoon to poke holes in the terrarium soil for placing plants. Firm the soil around the plants roots after planting. Do not allow plant leaves to touch the glass; that foliage will eventually rot.
Mist the plants with spray bottle or add drops of water with a syringe as needed. Fertilization is rarely required with terrarium plants; you don’t want the plants to grow too quickly. Prune back plants to keep them from growing out of bounds and to remove any dead foliage.
Get creative with your terrarium by adding small stones or pebbles to make a design. Even small items like faux mushrooms, pagodas, arbors or even pieces of driftwood. Keep in mind that a terrarium is a miniaturized version of a garden found in nature. They can be tended and enjoyed year round, regardless of the weather.
Questions or comments related to gardening? Contact Joleen at missourigardener@hotmail.com.