Nearly two centuries ago, Nathaniel Bagshaw Ward, an English physician and amateur botanist, made a surprising discovery. Ward liked to study moth chrysalises, which he kept secure in sealed glass containers. Inspection of one such container revealed that seeds embedded in a bit of dirt inside had germinated and sprouted. He left the container unopened and found that the plants continued to flourish, without any intervention, for two years, until the container’s seal rusted. When the little plants were exposed to the outside air, they died quickly.
Ward published his findings in an 1842 book titled, On the Growth of Plants in Closely Glazed Cases, and the rest is history. The sealed glass vessels were christened “Wardian cases” and their use created a revolution in botany by allowing shipments of live plants to be transported safely over long distances. The commercial implications were significant. The cases were also a boon to plant loving Victorians, who had to cope with foul air, drafty indoor spaces and other houseplant killers. They went crazy for the innovative containers, which became the ancestors of today’s terrariums.
I have always wanted an authentic nineteenth century Wardian case or box, but the survivors from that time are frightfully expensive. Even replicas of the sometimes fanciful Victorian Wardian cases are pricey. A terrarium is the next best thing and now they are back in fashion again. After years of envying other people’s terrariums, I finally decided to put together one of my own.
Mine began with a round, lidded container, about one foot in diameter and equally tall. In my dreams it is an elegant blown-glass concoction. In reality, I bought it for a song at a big box store. Still, it is glass and fairly heavy, with a secure lid. Next I detoured to the garden center for essential terrarium supplies: horticultural charcoal to keep the soil sweet, sphagnum moss and potting mix. These elements should take up about 25 percent of the container’s depth. Setting the terrarium stage, I started by layering one half inch of charcoal, covering it completely with a layer of moss and topping that off with potting mix to a depth of about three inches. My modern-day Wardian case was ready for planting.
I used an old iced-tea spoon with a long handle to install my plants and firm the soil, but some people may prefer to use a slender trowel or long tweezers, especially for narrow-necked containers.
In creating a terrarium, it is essential to pick a collection of plants that fit the allotted space—which is always less than you think—and thrive under similar conditions. Start with plant types that you like and see if you can locate miniature varieties. I wanted at least one flowering plant, so I started with a small African violet left over from a recent writing project. I added some lacy spikemoss plants—Salaginella–for greenery. My original concept involved additional plants, but as I installed the violet and moss, I realized that if they grew at all, the container would be too full. I filled in the spaces between specimens with some blue glass beads from the craft store, watered lightly and put a lid on it.
Now my terrarium is complete and not bad to look at, but it is still not quite right. I will probably change out the current plants in favor of some smaller specimens in order to create a more varied terrarium landscape. Micro-miniature violets, which are less than three inches in diameter, might do part of that job.
All kinds of plants succeed in terrariums. Since flowering specimens go in and out of bloom, consider companions with interesting leaves. Flashy polka dot plant—Hypoestes phyllostachya—a garden center and supermarket stalwart, features green leaves splashed with rose or pink. Another good choice, aluminum plant—Pilea cadierei—sports silver variegation. Small ferns always work well. For a larger terrarium, I like the whimsically-named lemon buttons fern–Nephrolepis cordifolia ‘Duffii’. Another option for both interesting flowers and leaves is a small begonia, like ‘Buttercup’, with quilted green leaves and lovely propeller-like yellow flowers.
Everyone searches for the no-work garden, indoors and outdoors, and a terrarium comes close. Think of Dr. Ward’s container, left undisturbed for two years. He was lucky that his chance seedlings developed into small plants. Your terrarium specimens may perform differently and eventually outgrow their space. Keep your terrarium tools handy to do necessary foliage trimming or plant removal. Most lidded terrariums need only infrequent watering. If excessive condensation appears on the glass sides, remove the lid for a few hours to air things out.
Some terrarium owners channel their inner decorators and install ornamental elements, including interesting rocks, tiny figures or structures that evoke fairy gardens. Terrariums are fun to do with children and, unlike many other child-friendly projects, require minimal clean-up and maintenance. My advice to parents—get your terrarium supplies now in advance of long winter storms.
Small terrarium-type plants are widely available in garden centers. For a wider selection, try Logees, 141 North Street Danielson, CT, 06239, (888) 330-8038, www.logees.com. Free catalog.