Terrariums are back in vogue
story and photography by Jodi DeLong
Mention terrariums to some indoor plant enthusiasts, and they will often get a (pun intentional) glazed look on their faces. They’re likely remembering big glass jars with tight covers, with a few straggling plants inside, humidity steaming up the containers. With the wrong species of plants tucked into these containers, they often developed root rot and other diseases, dwindled away and died, and yard sale enthusiasts could find former terrariums for sale a few months later.
It doesn’t have to be like that. Growing plants in glass can be highly rewarding, soothing and has the added bonus of adding charm and warmth to your home décor. But as with most things, there is a right way and a wrong way to grow in glass.
Here’s a little horticultural history. So many of the plants we grow today, both indoors and out in our gardens, aren’t native to us locally but were discovered by the so-called plant hunters of the 18th and 19th centuries. Dr. Nathaniel B. Ward was a Victorian-era British physician with a fondness for botany, and grew many unusual plants in his London garden. He found that the air pollution from the foundries and mills of the city prevented many of his plants from thriving. A chance discovery in 1829 led him to develop miniature, and often quite ornate, table-top greenhouses in which to grow his choice specimens, which did very well in the controlled growing conditions. The so-called Wardian cases became very popular with amateur and professional plant enthusiasts, and made it possible for those intrepid plant hunters to transport live plants back to England from all over the world.
Today, we generally refer to those glass containers, whether sealed or open, as terrariums rather than Wardian cases. You can find replica cases for sale online or occasionally at specialty plant shops, but for someone starting out with a terrarium, you may want to go with something smaller and significantly less expensive. With a little success, you may find yourself joining the indoor gardeners who are genuine terrarium enthusiasts. That would be the voice of experience speaking.
Another of those enthusiasts is Audrey Flanders, who owns Audrey’s Little Shop of Plants in Dartmouth and Halifax, NS. Visit either of her shops and you’ll find a veritable green paradise of plants in all sizes, including many grown in various sizes and shapes of terrariums. She’s a bona fide cheerleader for growing in terrariums, and a wealth of information for gardeners of all skill sets.
Part of the appeal of plants in glass containers is how they can safely be kept out of reach of pets and children, Audrey says. “They’re also a very stylish way of displaying plants for those who don’t want a clutter of plants everywhere,” she adds. “They’re especially great for offices and work areas, as they are fairly low maintenance,” when planted and tended correctly.
If you were a houseplant enthusiast back in the 1970s and 80s, you may have had seen or heard about only the sealed terrariums with that fitted cover on the top, or as a glass cloche that came down over a collection of small plants. Either way, these could be a bit of a challenge to maintain successfully. Too much direct sunlight or heat, and you could cook your plants—too much moisture, and even the most tropical-loving plant could develop root rot and die. Mildews and moulds sometimes showed up, and often the glass container would be covered in condensation, making it difficult to even see the plants inside.
Some people still grow plants in closed containers, but for the most part, you will have better success using open terrariums for many plants, Audrey Flanders explains. “Open terrariums are much easier to maintain, and we can use a wider variety of plants,” she says. Enclosed terrariums are great for very delicate or rare plants, but it’s best to start with something easy and move on to more challenging growing once your thumb is greener.
Using a glass container with no cover opens up a whole world of possibilities for objects to use as planters. Fish bowls or even an old aquarium, big glass vases or bowls, ornate glassware are all common choices, but you can also find dedicated containers, including hanging glass balls, which are delightful ways to display your special plantings—and keep them off tabletops and shelves, allowing you to have even more plantings, if you’re like some of us.
Audrey Flanders develop custom soils for her terrariums depending on the type of plants that her customers want. “We try to replicate the natural soil that the plants would grow in, so we make the soils in-house: succulent, cactus and rainforest soils,” she says. As an example, since a terrarium has no drainage, things like succulents shouldn’t be growing in rainforest soil in an enclosed terrarium. You can find recipes online for good soils for specific types of container growing, or go to a shop like Audrey’s for a custom mix.
Part of the fun of creating a terrarium environment is choosing the plants, and once they’ve been planted, adding accents such as stones, miniature statuary, bits of driftwood, semi-precious stones, and other curiosities.
Do you remember the so-called “tea animals” that came in packages of a certain brand of tea some years ago? The figurines were made of English porcelain and featured animals and nursery rhyme characters. I still have several of those figurines—the frog is in a small hanging terrarium with several air plants, and the gingerbread man in an open dish garden of succulents.
If terrarium planting sounds too much like work, don’t despair—you can purchase ready-planted and cleverly designed terrariums from experienced and knowledgeable people like Audrey Flanders, and just follow the straightforward care instructions.
Or…there are actually terrariums available with realistic-looking artificial plants in them, found at some garden centres for people who want even less maintenance but enjoy the look of green growing things. That’s always an option. We won’t tell on you.
After container selection, the biggest delight of any sort of container growing is selecting the plant species, and there are many choices for both open and closed terrariums. It’s important to select plants with similar growth requirements—if you’re doing a closed container for a lower light area, you wouldn’t want to put cacti or succulents in with ferns and club mosses. Any good plant shop or nursery that grows houseplants can help steer you in the right direction.
Great plants for your glass garden
Ferns: A number of fern species are well suited to growing in closed containers. You may need a fairly large terrarium to accommodate some, but others can be pruned to keep them compact, or don’t grow particularly big.
Club moss: You will often see a charming little plant called “frosty fern” for sale in winter months. This is actually a club moss called Selaginella, a similarly primitive plant (no seeds or flowers) that grows in wooded areas along with true mosses and ferns. It loves humidity and moisture and tends to do very well in an enclosed glass case.
Fittonia: The silver- or red-nerve plant adds a burst of colour with its deep green leaves patterned in white or red.
Venus flytrap: You often see these for sale in their own miniature “greenhouses” and they tend to be quite happy in an enclosed growing site.
Pilea ‘Moon Valley’: A fascinating plant with great textured leaves that are red on the undersides—which shows through on the leaves in some light conditions. It’s tolerant of low light conditions.
Hypoestes: The polka dot plants also provide welcome bursts of colour, with their leaves deeply patterned with dots and splotches of white, pink or red on deep green background. Authorities say they will die after flowering, but in all the years I’ve grown them I’ve never had them flower indoors.
Cacti: Many cactus species are slow growing, making them ideal for small display gardens. They belong in open containers, and of course they like it dry, and the biggest thing to remember is not to overwater them. If at all possible, avoid purchasing cacti that have been dyed garish colours, or those that have strawflowers—or worse, plastic flowers—glued to them.
Succulents: As the name suggests, these fleshy little plants also don’t require much watering, and thrive in a dry container planting. There are fascinating colours, shapes and forms, many with breathtakingly beautiful flowers. A personal favourite is the living stones, Lithops, which produce brightly coloured flowers when they’re happy, and which look like they belong with dinosaurs.
Air plants: We’ve talked about Tillandsia before, and they are delightful grown in an open and very dry glass container. Mine thrive on benign neglect—I spritz them with a misting bottle occasionally, and make sure they get moved around if they look like they want more light. Some of them flower when they’re happy, which makes the gardener happy.
Earth star (Cryptanthus): These are bromeliads related to Tillandsia, known for their colourful foliage of green with red, pink, orange, or gold-variegation. They can be grown in closed containers but watch them carefully for too much wet; a better choice is to put them in an open terrarium and mist them regularly. They occasionally flower, but their main appeal is their foliage.