In February, my coffee table suddenly becomes incredibly interesting with the addition of several terrariums. It’s a winter thing. Remotes, pretzel crumbs, and the everpresent hint of dust are still there, of course. But the table is situated such that the morning sun hits it so perfectly that I can’t resist the urge to grow something under glass. Who am I kidding? I can’t resist growing anywhere!
I find that as I get older, I become more in tune with light. How it moves. Where it rests the longest. But really, I’m assessing what I can grow. The thought process is the same whether I’m gardening indoors or out. It’s just that in winter, I prefer the simple pleasure of looking into a self-sustaining little world, moisture dripping down the inside of the glass. The occasional tip of the cloche to take in the earthy smell. It’s lovely. Peaceful. It suits the stillness of the season.
The most appealing thing about growing under glass is that it requires very little attention after it’s assembled. It’s in its own little world, something terrariums and me have in common. Other than the occasional check for dryness, which varies depending on the type of enclosure, light exposure and plant, it is a garden that requires little intervention. And the beauty of it is, you most likely have a few things already in your home to get you started.
Selecting the Vessel
The most time consuming part of starting your first terrarium is accummulating the supplies which, to me, is part of the fun. First off, the vessel. And if you have a mason jar, and I’m guessing you might or know someone who does, check “vessel” off your list.
Otherwise, a quick trip to a place like Homegoods, Marshalls or TJ Maxx will provide you with plenty of very affordable vessels perfectly suited for terrariums of all shapes and sizes. I found the glass options above at Homegoods. At $14.99, the apothecary jars were the most expensive. The glass cloche was $5.99 and the bowl vase was $10. Nothing that breaks the bank.
If you choose a cloche, you’ll need a base if it doesn’t come with one. Choose a base with a slightly wider diameter than that of your cloche. This could be a ceramic plate, a terracota saucer. I got lucky and found this one (in the above photo), chipped and damaged in a clearance section at Homegoods and it just happened to work with the cloche. I think its appeal is enhanced by the imperfections.
For cloches, you have two options. Plant directly on the platform, which requires a little finesse as far as mounding the charcoal, pea gravel and soil before adding the plant. You can see how I did this in a brief reel I created for my Instagram. If you go this route, you want to be sure that the plant you pick is not too tall for the height of the cloche. Otherwise you end up with an unhappy plant.
Option two, and probably the easiest one, is to pick a small humidity loving houseplant like a pilea, plant it in a pretty little container and place it beneath the glass cloche. It’s just as attractive and a bit easier to handle. Boom! You’re done and your terrarium is complete.
If you choose an apothecary jar, a mason jar, or an open bowl, the important thing is depth. Because terrariums lack drainage holes, they need to be deep enough to allow for a half to one inch of the charcoal/pea gravel mix, as well as two to three inches of soil. The big difference between an enclosed terrarium and one planted in an open bowl is their evaporation rates.
Enclosed terrariums are little hot houses that can self sustain sometimes for months before they require a drink of water. Open bowls require more frequent watering. Treat these as you would a regular houseplant, with a weekly finger check for dampness and water accordingly.
When I first started making terrariums over a decade ago, it was difficult to find one of the most important ingredients – horticultural charcoal. Not to be confused with barbecue charcoal, totally different animal.
At the time, it was only available in my area at pet stores in the fish section for aquarium owners who use activated charcoal for water filtration. Horticultural charcoal does the same thing and is crucial to keeping the environment clean and your plants happy. Terrariums lack drainage so the charcoal mixed with pea gravel takes the place of proper drainage.
You can find pea gravel at most garden centers and home improvement stores for a few bucks. A small bag of horticultural charcoal will cost about $5-$10 depending on the size. Buy the smallest bag you can find. You won’t need much, just a handful or two for the base of the terrarium.
For soil, I use a succulent mix available at most home improvement stores. Sheet moss is a nice finisher as it covers up all the soil and just makes a nice green platform for the main event…
Unfortunately, you can’t just go pick out any plant that appeals to you. For instance, succulents will die faster than you can blink. They’re not suited to humid environments, which means humidity loving plants are what you’re looking for. Think tropical. If it can survive in a rain forest in Borneo, you’re good. Otherwise, forget about it. Here are my suggestions for plants. I’m sure there are plenty more but these are widely available and ones I’ve used with great results. Just be sure to pick plants in small containers no larger than three-inch pots. Any bigger and you’ll have a helluva time squishing them into an already tight terrarium.
- Tillandsia aka Air Plants
- Venus Flytrap
Fertilizer is unnecessary for terrarium living. It’s food and food makes things grow big and big isn’t what you want. You don’t want your little world outgrowing it’s greenhouse too fast. They’ll grow, but at a much slower rate than they would if you fed them, so no fertilizer. Eventually, they’ll get too big. In which case you can remove the maturing plant to it’s own container and replace it in the terrarium with a smaller one.
For a complete play-by-play on planting your first terrarium, check out Here She Grows on YouTube. I think it’s the best way to show you how to plant your terrarium once you’ve assembled all the ingredients. Happy planting and I hope terrariums will scratch that gardening itch until spring arrives in exactly 30 days. Not that I’m counting or anything.