What do you do with a green thumb during those cold winter months indoors? Houseplants are one option, but the heat and dryness of furnace-pumped warm air can bake a poor African violet in no time, and those pesky whiteflies too often spread devastation over softer leaves. Not to mention the long stringy stems reaching for the sparse winter light. No, what you really need is an indoor greenhouse with warm moist growing conditions for your little beauties. The answer? Glass bottle terrariums!
This ingenious concept was invented by Victorian age explorers, who would take plant and insect samples from faraway lands and store them in corked glass bottles for the journey back to Britain…. If the balance is right, plants can live indefinitely inside a closed glass environment. Put in just a small amount of water and cork the lid – the roots will take in the liquid, and then respire it out through their leaves.
The moisture then collects on the glass surface of the jar, runs back down into the soil, and the process begins again. Terrariums make lovely windowsill gardens, tabletop accents, and friendly bedside companions, and are a great way to bring a garden to a small space if you live in an apartment without a yard. Best of all, you never need to remember to water them!
To build a healthy Terrarium:
Select a glass jar or bottle with a sealable lid.
Old canning jars work best, or kitchen bottles with wide necks and corks. You need something with a neck large enough to fit your hand through, or else you’ll be stuck trying to tend the plants with long tweezers. Choose one that is a good size, typically 6 to 12 inches tall, and 4 – 6 inches in diameter.
Gather the materials for your growing conditions.
You will need fine gravel, sand, ground charcoal, and good quality potting soil, preferably from a garden center, rather than scooped from the outdoor garden.
Put layer of gravel about ½ thick into the bottle first, and then a ½ of sand. These will act as a drainage layer for the water. Then sprinkle a ¼ inch layer of charcoal over the sand. The charcoal filters the air and water within your ecosystem, keeping it clean for the plants to breathe. Finally, fill up the bottle to about ¼ full with the potting soil. If you have a small bottle, you can do with just an inch or so, but if you have more room, use a thicker layer, and your plants will be able root more strongly.
Choose suitable plant species.
You’ll want to choose slow-growing plants, with a small average growth height, who favor warm moist conditions. A cactus won’t thrive in this type of terrarium, and similarly a geranium would never fit. Fittonia, Calathea, and Helxine (baby tears) are all species which work well inside terrariums; you can find more suggestions here , or just browse your local garden center for small-leaved, humidity-loving varieties.
Plant, water, seal and enjoy!
Carefully plant a small sample of your plant in the soil. Don’t use too large of a sample, make sure you give it some room to breathe and grow! Water with about a tablespoon and a drop of liquid plant food, just to get it started, although you wont want to give it food very often, since you don’t want it to outgrow its home. Cork the bottle, or screw on the lid and set it in your favorite room to keep you company.
Terrariums like a little ambient natural light, but not too much direct sunlight. Direct sunlight will cause the internal temperature to rise, and form lots of condensation on the glass. This pulls all the water out of the soil and plant and consequently parches it.
Watch your terrarium closely at first, and discover what balance of moisture and air it needs. Depending on the size of the plant it may need more or less water than you’re giving it. If it seems as though there is too much water, leave the lid off for an afternoon, and let it dry out a bit.
Make sure you remove any dead leaves etc as soon as they fall, and trim back the plant if its getting straggly or brown. Plant matter left to decay will begin to mold and spoil the environment for the rest of the healthy plants.