Spring is still weeks away, but winter-weary gardeners can satisfy their desire to get their hands dirty and watch things grow by capturing a little nature under glass.
A terrarium brings a miniature garden to your desk or tabletop with minimal effort, says Tovah Martin, author of The New Terrarium, a how-to from Clarkson Potter due out Feb. 24. "It's so easy. It's one of the easiest ways to indoor garden besides growing succulents and forgetting them entirely," she says.
Picture a petit woodland glen on your coffee table with moss, ferns and ivy nestled around a pine cone. Or a tiny beach retreat in your office cubicle featuring sand, shells, a sliver of driftwood and an air plant. For those who don't have the time or space for a garden outdoors, a terrarium is a way to enjoy nature with minimal work.
Although there are enclosures especially built for housing terrariums, part of the fun is using materials you already have around the house or can pick up at the dollar store to create your little garden. A candy dish, an old goldfish bowl, a vase or even a Mason jar can be turned into terrariums, Martin says.
The size and number of plants you choose will depend on the size of the container, but in her book, Martin advises gardeners to "start by choosing plants you want to live with."
Moss, small ferns, African violets, ivy and miniature orchids are good candidates for terrariums, she says. About the only plants that won't work are succulents and herbs because they cannot tolerate the humidity.
Before planting your terrarium, clean the container thoroughly, but avoid household cleansers. Then place a layer of pebbles and charcoal in the bottom of the terrarium and top with a layer of potting soil. "The place where most people err is they don't plant the plant in the soil," Martin says. "You need to tamp the soil down. The soil needs to be in contact with that root ball. It's got to be in close."
Once you've assembled the terrarium, choose a location for it that is away from strong, direct sunlight and heat sources such as radiators because under glass the plants can become too hot. While light isn't a concern in the winter, in the summer it's best to avoid the south-facing windows that receive intense light, Martin says. "When in doubt, push your terrarium away from light sources," she adds. "It's amazing how little light something like a fern or moss needs."
The other amazing thing about a terrarium is how little maintenance it requires. If the terrarium is closed, the plants may need watering only once a month. If the terrarium is open, such as a goldfish bowl, it may require more frequent watering, but still less than the plants would if they were in the complete open.
Because the object is to keep the plants small, they do not need fertilizing, Martin says. But, she says, the plants should be monitored for mold and fungus. If there are any signs of disease, it should be removed right away.
Martin says she rarely has a problem with disease and the plants in her terrariums require little other than an occasional snip with a pair of long-nose scissors if they get a little too big. "I found that I hardly ever have to fiddle with it for a year."
When the plants do need a little thinning, that can be part of the enjoyment, she says. "This is all about the interaction and living closely with nature."
if you go
Garden writer and lecturer Tovah Martin will speak at the Walters Art Museum at 1 p.m. March 8 on "Infusing the Garden with Personality." Tickets are $25 for members and $35 for nonmembers. Go to thewalters.org.