November 22, 2014



I secretly love terrariums. Like many of you, I often converted most any glass container I could find as a kid - old canning jars, old aquariums, even old plastic shoe boxes which I could convert into magical, moss filled terrariums. Hey - it was the 60's and 70's and it happened to be very trendy towards the end of the 70's!

I still enjoy terrariums, they are just so magical, but today, in our overly DIY world, the term 'terrarium' has a broader definition - some blogs advise you to plant succulents in an open glass bowl -ok, not really a terrarium, but then again, not a good way to grow anything. And then there are those very hip hanging glass spheres with nothing in it much more than a tuft of reindeer moss and an airplant.  Still, not a great or effective way to grow plants, but there are so many vessels to choose from today, that really, there should be no excuse for any pocketbook from industrial kitchen jars at Target meant to store cookies or sugar, to more costly designer cloches and domes. I spluged on this one a couple of years ago at Terrain - and it keeps me entertained in the winter months.

I won't lie - there are far more poor directions on-line then there are good ones. Just google the phrase Make a Terrarium, and you will see. Most err on style more than botanically interesting or even botanically correct plantings - succulents cohabitating with ferms! I know, I know - we all did that, so yes - it is one way to learn. And there is no denying that terrarium craft is one of the best ways to get kids interested in plants. If your child is harping for a pet this Christmas, why not offer a nice terrarium instead?

Assembling a good, proper terrarium is akin to assembling a good, proper salt water tank. Perhaps not as specific, but you get the general idea -- no freshwater goldfish in with your salt water sharks, for example.  I know - it seems stupid to say such things, but beleive me - I can't tell you how many cacti with african violets and philodendron I have seen in just the past week! Look - you are creating an environment, a specific habitat. So whether you are recreating  a tiny bit of the high elevation rain forest on Mount Kinabalu in Borneo or a lowland rainforest with napenthes and a few other insect eating plants, please get interesting enough to research a bit - essentially you are creating a biosphere. I would imagine that if you really get into it, building a good, real terrarium can be not only a learning experience for the whole family, it can be truly fun. No need to be so accurate that you only use plants from Borneo, but learm what grows well together - ferns, mosses and begonias for example.

I start by laying a layer of gravel in this Wardian Case style terrarium. It has a copper liner, but still drains so I am potting it in the greenhouse first, and I will bring it into the house in a few days where it will sit on my blogging desk near a north window for most of the winter.

Terrariums have a long history dating back to the early plant explorers who used such 'Wardian cases' in which to bring back plants on sailing ships in the 18th and 19 centuries, later, in the Victorian era, such cases were used to grow fussy, difficult or challenging collections of precious plants which required special conditions. Of course, this is how I like to treat my terrariums - a containers for very special plants, some of which actually prefer the conditions  more than they do inside my larger glass greenhouse.

Even though I don't mind seeming bad advice on other sites, as it seems people still enjoying making terrariums, but it does bother me that few sites seems to offer good advice. You see, terrariums culture is a rather precise science - and there are plenty of plants which grow extremely well in the enclosed environment of a glass terrarium, but few if any of these plants are ever seen featured in blogs or large magazine brand websites which seem to all prefer to show succulents or cacti along with moss, stones and glass. 

I collected various mosses from around the back yard and from the woods out back.

OK, while I am on my soapbox again - endulge --  have no idea how many times I am asked by various major home lifestyle magazine to write an article about this or that - currently and article about good winter  houseplant suggestions  (currently, for a February issue). I complied, then my choices were changed and they asked me if it was OK. I wasn't OK because their editors felt that they wanted to  feature miniature Anthuriums (really). A week later, the editor sent me another note saying that they changed their mind again, because Anthuriums were poisonous they discovered, and asked if I then could suggest something else ( I had originally suggested a few new citrus and colorful rhizomatous begonias). In the end, I heard nothing, but it does show you how such topics are researched and written today.

Of course,  we should not forget the 80's when sandart came onto the scene - jars with layers of multicolored sand in groovy tones of the desert and sea. These were often planted with cacti and succulents - some of the worst candidates for air tight glass containers. If you are interested in making a terrarium, there are ways to create these closed in environments where the plants will actually thrive. There are so many misguided directions out there on the Internet - ranging from succulents like living stones ( Lithops) and cacti in sand, to air plants and moss - all certainly cool looking, but terrible candidates for a terrarium.

Looking around the greenhouse, there are a few plants which I felt would do well together in a terrarium. The ferns are smaller growing species, and the begonias are smaller growing species that actually prefer terrarium culture.

Choosing plants that really demand terrarium culture - really - there are plant that prefer terrarium over any other way to grow them, even a greenhouse - warm, moisture loving jungle plant like ferns and mosses do well together, as do certain gesneriads (African violet family). Many Begonia species and hybrids love glassed in containers.

Plant similar plants together - for example, not all orchids love the environment of a terrarium - in fact, very few orchids do, and any that you buy at Home Depot or the supermarket won't do well in one - rather, it's some tiny species that particularly do well like Dracula and a few tiny Dendrobium species.  Do a little research and you'll be surprised at how botanically interesting a terrarium can be - combining rare orchids like the tiny Dendrobium cuthbertsonii selections with other small terrarium orchids like the pleurothallids - check out Mountainside Orchids in Vermont for some amazing terrarium orchids and begonias.

I considered using the Kohleria, a relative of the African Violet but even with three plants, I think this large terrarium was already over planted. I can always pot this up under a dome or in another terrarium. It's not a perfect candidate for terrarium culture, but I know that my greenhouse is too cold, and my house too dry for it.

When I plant a terrarium, I like to combine plants that prefer the same conditions. A terrarium won't last forever, most need to be replanted every year or at least, edited but again, these are plants, and they grow. If you need to replant your terrarium, you are probably doing something right.

Terrariums are best if kept clean, so I start with a good commercial potting mix. The Perlite in it can be unattractive though, so I mound the soil higher in the center, and use gravel at a higher level on the glass. One would want to avoid white Perlite from floating up onto the moss, but garden soil would be too dense for me to use. A good compost if you have it will do well too. Fast draining soil that holds moisture is best, and most woodland plants, whether they come from the jungles of Ecuador or from upstate New York prefer fibrous, damp aerated growing material. In most cases, a deep layer of moss will do for these plants, as would live sphagnum if you can find it. I only use a half an inch of soil, relying on moss mostly to create my growing medium.

Tucking moss in under leaves of plants that tend to lie on the ground such as the leaves on this Begonia crispula will help keep the leaves healthy.
 Plants are added in thoughtfully, again, selecting species that do well together. I am limiting myself a a few select begonia species, a small rare Begonia from Brazil called Begonia crispula a plant that requires humidity near 85 - 90% - (You can find Begonia crispula here but they are sold out at the moment - it's where I got mine). Begonia crispula is just so choice and precious, that it will be the centerpiece of this terrarium, and a much larger growing begonia (B. paulensis) which will only spend the winter in this protective case. If it grows too large, (and it will) I can always remove it. Until then, it adds a nice texture to the planting.

Along with begonias, ferns are the perfect companion plants for terrariums. This Polypodium formosanum (you can find them on-line here at Black Jungle Terrarium Supply) which has these attractive almost teal-blue creeping rhizomes.  This is a smaller growing fern which I like because it looks like one of our native Polypodium virginianum. This tropical Poly has colorful rhizome which in some light conditions can look pale blueish green, almost like jadite. This is a fern that really demands either greenhouse or terrarium conditions, so it's a difficult houseplant unless one has a very humid house.

I keep a few of these Polypodium formossanum in the greenhouse, mostly in handing baskets where it makes a very nice, but slightly fussy specimen plants. Forget watering it just once, and it will loose it's leaves. I look for rhizomes that I can cut which have a few leaves on the, and these two above are starting to bury themselves near the edge of the pot - so I will cut these with a knife, and remove them for the terrarium planting.

The rhizomes come out easily, with a few roots. IT will transplant well with little disturbance, and by next summer, I can remove it and replant it into a larger container - most likely just one with sphagnum in it, which this species prefers as a growing medium. Until then, my terrarium will act as a propagating case, and no one will know the wiser. I have an unknown Davallia species which I too added to this planting. Another fern, similar to the common Rabbit's foot fern.

No plastic deer for me. A few pieces of bark from where I collected my moss with lichens on it will add the perfect color and tone for this case.

A good drink of water - I mean, a really good drench as there is a pan with drainage in this, is all that is needed. I will rarely have to water it once it is in the house, so I want a good soaking so that no dry soil exists.

SO, I am planning on driving to Black Jungle Terrarium supply this weekend, so I may update some of these plantings. If so, I will add the images here ( you know that I will!). But it all depends on if this nasty cold goes away soon.


  1. One of the foundational items for my love of plants was a terrarium I made out of sheet glass and electrical tape when I was around 6 to 8. It was less than a cubic foot, but I grew all sorts of things in it. I remember Albizia and Robina seedlings, and lots of beans. I'd get little Peperomias from the Grants store accros the street. When the plants outgrew the terrarium, I'd pot them up. Then my cat would eat them. :-)

  2. Oh MIke - flash back to my past! Grants! Red Slider Turtles, Canaries and parakeets - Christmas cookies that were awful, but hey - it was Grants!

  3. Anonymous9:09 AM

    I have incorporated lichen encrusted bark and sticks into terrariums before, and found that sometimes the fungus side of the symbiotic lichen equation decided to separate and grow on its own. Has anyone else ever had this experience?

    -Ash Baron

  4. More Grants 5 & 10 cent store is flashing back to me too, now that you mention the pet department. I used to buy the 6 foot long balloons and play with them a lot.

  5. Do you not worry about bringing in pathogens with the moss, twigs and lichens that you foraged from the back 40? It seems to me that with the care taken in sterilizing containers and commercial potting mix that this would be an issue...

    That said, it looks great. And I am always looking for an indoor use for the lichen covered branches that fall in the yard,

    1. I should have been clearer - use sterile soil in an effort to reduce the chance of introducing greenhouse and houseplant pests. I'm not worried about woodland insects or fungus, only greenhouse insect eggs and larvae - no need for scale, mealy bugs or white flies if I can help it. I actually would like woodland fungus and microorganisms in the terrarium.

  6. Jessica8:43 AM

    Lovely post - and thank you for taking a stand against the weird succulent/moss terrariums that have been making the rounds lately. Maybe we should have a hall of shame for the best of the worst?

  7. Great pictures mate and lovely terrarium you got there. I think you just missing a pet there. As a fan of reptiles, I would love to see a snake or a lizard in there. :)

  8. I like the glass bowl versions and the aquariums. The idea of creating a mini ecosystem and adding in miniature items, like a Christmas village home that lights up with battery turns into a "live" Kincaid art piece. Great gift idea for the Christmas season. Great post.

  9. Great job you did there! The terrarium looks amazing!

  10. It's nice to see someone else putting such care and thought into their terrarium design - you're right that many guides online are absolute rubbish, but you've done a spectacular job when it comes to plant selection. Wish I had enough room for such a large terrarium in my apartment =\

  11. I love the terrarium you have in this post. Can I ask where you purchased it? I would love to have one in my home.


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