In the chilly ides of January, when New Years has passed and it seems an interminable length of time before you can start planting, there’s nothing quite so satisfying as planting a terrarium.
Once known as ‘Edwardian cases’ and the vehicle by which European explorers brought all manner of pilfered plant material safely home over long ocean voyages, terrariums today still exude a certain romance combined with an aura of scientific inquiry that is irresistible to the casual botanist.
Furthermore, they are easy, so easy. I swear it! I know what you’re thinking….Erin do you mean easy like a walk around the block? Or a two mile urban hike in pinchy new shoes? (Sorry Sara!)
They really are easy. The hardest part is gathering the materials, and that involves a little plant shopping. I know some of you shuddered at the dreaded ‘shopping’ but plant shopping is fun. No judgmental mirrors or salespeople eying you as you squirm into this year’s textile version of torture for anyone over the age of thirteen….Nope! You just get to go to a pretty nursery somewhere and look at green things. (If you’re in the Seattle area, go to City Peeps and say hi for me)
I’m going to make it even easier for you. Here’s your shopping list and a link to a printable version here.
1- Some type of vase, jar, case that allows enough room for your plant and their root systems. I’ve found a lot of great containers at Goodwill and Value Village. Get something pretty or interesting or fun. Something you’ll enjoy looking at for the next few months as you chafe to get outside. Although once you start growing terrariums, you will find them to be an end in and of themselves.
You can get a vessel that has a lid, or one without. In the case of an open terrarium, you will have to water a bit more often. In the case of a closed terrarium, there is less watering, though you will want to keep an eye out for any type of rot. *Note: Both of these are easy to do, so pick either or both.
2-A neutral potting soil. Something lightweight, that drains well. Don’t let them sell you anything with fertilizer in it. This way your plants will stay relatively small.
3- ‘Horticultural’ or ‘Activated’ charcoal to sweeten the soil, filter the water and prevent stagnation….What in the world does ‘activated charcoal’ mean Erin?
Okay, the shortest explanation I can muster. Basically, many, many little pores are added which makes for more surface area and a higher absorption rate. This increases its ability to filter the water in your terrarium. Cool huh?
4- Some pea gravel. Or any little rocks about 1/4 inch or smaller. These will help with drainage, since your terrarium doesn’t have any holes in the bottom, nor should it.
5- Sphagnum moss or fiberglass screening. And this is totally optional! An extra layer to separate your soil from your gravel. As per advice from some gardening friends, I haven’t used this in awhile, and I’ve found it easier to get in more soil for the plant to grow. This tutorial won’t be using this layer, but if you’d like, just wet the moss first and tamp it down over the gravel. Or, cut some old window screening and lay that down. Questions? Drop me a line in the comments section.
6- Doodads. Most likely you won’t have to shop for this but can find these in your home or on a nature walk. (Good excuse to go outside and get some fresh air for those of you with cabin fever) By doodads, I mean shells, rocks, mossy twigs, objets d’art, old toys…anything you think would be fun in your little garden. While you’re at the nursery, check and see if they’ve got a bonsai or miniature gardening section. You might find something there as well.
7- Plants! Yay, see what I did there? I’ve saved the best for last. What type of plants? Glad you asked. Terrariums increase humidity, this can really help plants growing in our modern homes, which tend to have very dry air. You can grow all manner of plants much more easily, because they’ll be getting that nice, moist air they so desire. Also, the glass of a terrarium does block some light, so it’s good to look for plants that don’t mind a bit of shade.
Here are some likely prospects:
Peperomias– These guys come in a variety of colors, and textures and are otherwise known as ‘radiator plants’ because they’re so easy to grow.
Pileas – Tropical plants that just love terrariums. Specifically, “aluminum plant” is a popular choice for terrariums.
Mosses– Selaginellas or ‘Spikemosses’ are a great option. But moss in general, with its tolerance for low light and high humidity is a fantastic terrarium plant.
Ferns – These are probably best for your larger terrariums. Make sure to get a fern that will be happy at indoor temperatures.
Tillandsias or ‘Air Plants‘- Sort of. These tree-dwellers will do best in an open terrarium because they like good air circulation. That said, they can be very happy in terrariums, given enough light. They just love the humidity.
Try any plants you like. It’s good to go for a variety of texture, foliage and color. Rummage through the houseplant section of the nursery, and see what you can find. Chat with the nursery staff, see what they enjoy growing. Maybe, experiment with some outdoor plants such as scotch moss or mondo grass. Remember, it’s your terrarium. Just as in your garden, if a plant is unhappy, dig it up and try it somewhere else.
Now that you’ve got all your ingredients, the fun begins. Start by making sure all your containers are clean and dry. I like to wash mine with a mild bleach solution, just to avoid any stray critters who might like to make a home there. You can see that I’ve chosen rather tall, narrow containers here. That’s because I’m planting a group of terrariums for my desk. I see them as inspiration for future gardening posts. If your containers are narrow, you may want to rustle up an old chopstick or stray pencil to use as a tamping tool while planting.
Alright, time to put on your garden gloves. Start with laying down about an inch of pea gravel in the bottom of your terrarium. Then take a generous handful of charcoal and mix it in well. (That handful of course becomes more of a fingerful when working with bottle-sized terrariums as above)Lastly lay down another inch to two inches of nice sterile potting soil.
Now start planting! And keep in mind, while you don’t want to unduly disturb the roots on these tiny plants, most plants are hardier than you think. If your plant has a bit too much root mass, feel free to split it a bit down the middle and lay the roots out. I usually shake off a bit of the soil around the crown as well.
Notes on design- As with outdoor plantings, think about creating visual interest by playing with a diverse palette of colors and textures. Consider what creates the best contrasts, both within your container and in the space you’ll be placing it. Also, try planting in odd numbers. Three plants create a lovely vista for the eye, even in miniature.
Watering– Now that you’ve planted your terrarium, you’ll want to water it. Because there is no drainage in this container, you’ll want to think in terms of a gentle spring shower versus a drenching. The soil should be damp versus wet.
Time for a few furbelows. Once the water has settled in, you can arrange you shells, twigs, pinecones and what-not to what pleases your eye. After all this is your terrarium, and half the fun is rearranging over the long winter month, taking out, adding in and just general pleasant fussing.
Ta-da! You’ve got a tiny garden to grace your desk, tv stand or what have you. When siting, avoid areas of direct sunlight. The glass can magnify the light and sizzle your plants quite quickly. Avoid heating vents for a similar reason.
The Care and Feeding of Terrariums:
“Health and Safety” as they say. While your terrarium shouldn’t be the source of much back-breaking labor, there will be some care needed.
Check your terrarium regularly for signs of decay. Be a friend. Prune back any yellow or damaged leaves, or wilting flowers immediately. Keep the glass clean (NOT with Windex, a soft rag should be sufficient). This will help prevent fungal/bacterial infection. If you should see mold develop, remove immediately. If it is on a plant, remove that plant too. You must act quickly and without mercy. Terrariums are an environment where once fungal problems are introduced they can spread quite rapidly.
If you do find mold, once it’s removed, you might CAREFULLY ventilate your terrarium for a few days. Open it up and set it near an open window during the day. Of course, keep an eye out for extreme temperatures. But it’s amazing what a little breeze can do for the health of an ailing terrarium.
Which brings me to the next thought, keep a light hand on the water. The amount of watering you do is of course different for closed vs. open terrariums. Closed terrariums can sometimes go months without needing water. Our open terrariums should be checked once a week, not watered that is, checked. Stick your finger in, if the dirt is dry, go ahead and water. This will vary by season, weather, sports victories etc. As you gain familiarity with your terrarium, you will get a better sense for it. But do keep an eye out. And finally, rotate your terrarium occasionally, this will even out light distribution.
I hope this helps you create your own indoor garden to enjoy this winter. If you’ve any questions, do drop me a line in the comments section. And if you do plant a terrarium, I hope you’ll send me some pictures!