Most people know about aquariums—the glass-enclosed cases for the study of fish. But not so many know about terrariums—the glass-enclosed cases for the study of small plants. These are often called miniature gardens or glass gardens.
How did glass gardens originate? One favorite tale is that one hot summer day a man walking through an arid field where all plant life was withered and dry saw at his feet an unbroken bottle lying on its side. Inside the bottle was lush green growth. Through wind and rain, soil and seed had drifted into the bottle; and there, protected from the elements, the seed had germinated and grown. The moisture within the bottle condensed each day and fell upon the little plants, and so they grew in their own small hothouse in the parched field.
A glass garden is a joy to see and easy to make. Here are some suggestions for making one.
The container should be clear, uncolored glass of any size or shape, from a six-gallon water jug to a four-ounce jar. It may be covered or left open. Small containers of two-quart size and under are easier to plant and maintain, while large ones are more challenging.
To make a terrarium, first place a layer of charcoal inside the clean jar, one-half inch to one-inch deep, depending on the jar size. Because the jar has no drainage hole, the charcoal acts as an absorbent for the moisture to keep the soil from souring.
For the planting mixture, some growers use only sand; others prefer commercial potting mixtures. Plants grow more slowly in sand, but even after eighteen months to two years they look green and healthy. Coarse sand is more attractive than fine sand. If beach sand is used, rinse out the salt.
A potting mixture looks better than sand in most gardens, but because of its richness the plants often outgrow their glass houses in a few months. A mixture of the two works well.
After the dry soil or sand is added to the jar, shake it gently so that the soil filters down into the charcoal. There should be about one-half inch to three inches of soil on top of the charcoal, again depending on the size of the jar.
Now, carefully pour in just enough water to moisten the soil. Mix the water and soil gently. If it’s too dry, it won’t hold the plants in place; and if it’s too wet, it becomes soggy and unmanageable.
From here on, what goes into the garden depends on the grower’s imagination. Besides plants, the garden may contain such items as seashells, acorns, bark, driftwood, or rocks. Some gardeners create small landscapes by using tiny dolls and animal figurines. For example, a one-inch-high toy elephant in a ten-inch-high jar of moist green plants gives an eerie jungle illusion.
Mosses add color and interest. Nearly every area has moss or lichen on the ground at the north side of homes; it may also be found clinging to the sides of ditch banks. One of the most appealing gardens is a closed four-ounce apothecary jar containing only moss and a piece of rugged bark. On the dreariest day a peek into this tiny jar is cheering.
For planting the garden, these utensils are useful: tablespoons, table knives, kitchen tongs for prickly cactus, syringes and plastic spray bottles for cleaning inside the jar, and a long dowel or yardstick for positioning plants in tall, long-necked jars.
In planting your garden, place the rocks first. Then position the plants, and finally add the shells, moss, or other similar items. A garden that’s planted with all objects on a level surface is not as interesting as one that has the soil built up against a rock, or a plant elevated.
What kinds of plants may be used? Just about anything can be tried, but some plants do better than others.
Cactus and succulents grow slowly and do well only in an open jar. Planted in a closed jar, they quickly become pale and “leggy.” For a realistic-looking desert scene, use cactus, rocks, sand, and a tiny sun-bleached twig. These open gardens need sunshine and regular watering.
Some of the most beautiful gardens contain African violets, which thrive in the warm, moist atmosphere. Be sure the container is large enough to allow the leaves to spread freely. The plant may be put directly into the soil or left in its own pot and sunk into the sand and charcoal. This garden may be left open or partially closed. It needs good light but little or no sun.
Baby tears, small palms, miniature ivy, philodendron, wild strawberry, strawberry geranium, pelargoniums, and all varieties of peperomia do well. Small woodland plants are exciting. They may be gathered from their native areas or ordered from seed catalogues.
Most of the terrariums sold at florists’ shops are open to the air, and plants grow well this way. The closed jar is more tricky. Each night moisture should condense on the underside of the cover. If there is a good balance of moisture and content, water may seldom or never be needed. A friend has a garden in a six-gallon water jug. In its three and a half years of existence, it has never been opened, and no water or air has entered. Two plants, a miniature palm, and a wandering Jew are thriving.
If no moisture clings to the cover, the garden needs water. If the whole inside of the jar is covered with moisture, it is too wet, so leave it open for a few hours each day until correct balance is found. Even most closed gardens need an occasional airing. Closed jars should not be exposed to the sun, as the heat and humidity soon rot the plants.
To keep your garden beautiful and healthy, remove dead leaves and trim plants when they become overgrown.
Even those who say they can’t grow a thing will find delight in a glass garden.