Today I attended a lecture at Michaleens on making your own terrarium by Barbara Bryant. I first noticed something along this line years ago, when the nurseries began selling shallow pots full of tiny plants and little objects, like tiny fairy landscapes. I still love dollhouses and miniatures, and the combo with living plants was very appealing. I couldn’t bring myself to make something else to sit around the house, but I did create a small dry stream bed in the same spirit. As for terrariums,I remember when I was a kid,we lived in an apartment complex next to Sapsucker Woods. I had always lived in towns or cities, so I was thrilled with the tree climbing, water splashing,outdoor experimenting possibilities.One great idea I had was to grow moss indoors. Using my observation that I found it in shady spots,I figured it would be happiest in the hidden,lightless room under the stairs I was so fond of myself.
Mysteriously, it was not.
Anyway,since then,terrariums have evolved into a rather popular pastime using the oddest glass containers you can find filled with stones and moss and whimsical objects.
Number one: The Container
Anything goes, as far as I can tell, as long as it is clear glass. Terrariums can be covered, but then they will stay very moist,need to be opened occasionally, and perhaps fog up. The terrariums on display were mostly open.
Number two: The Soil
Start with a layer of stone at the bottom for drainage. After that, you can build up using larger stones, or bury a lighter block of material (to keep the weight down) and cover it to get variation in height.Remember that the layers will be visible, so use interesting stone. For instance, in the demonstration terrarium, she tucked sheet moss around the bottom.
Create little level areas where you will put the plants and fill these with a soil-less mix.
If you are growing succulents, mix the soil with chicken grit to improve drainage.
Number three: The Plants
The plants need to be small, either by nature or by a willingness to be pruned hard.Since glass magnifies the sunlight, terrariums should not be directly in the light (though blooming or variegated plants do need more light).This makes them especially suitable for growing ferns and mosses, Ferns are also more suitable to closed containers.Although it was mentioned that moss prefers acidic soil,I’m pretty sure that moss is not so much about pH as about lack of competition, and of course, doesn’t actually have roots or need soil.Bromeliads were mentioned, and I expect they would be happy with this sort of treatment. We weren’t shown any orchids, but were told they would probably do well in terrariums, if not over watered.Interestly, she said air plants (Tillandsia),while not needing soil, prefer to be soaked for up to 8 hours twice a week. Another death explained.
It is also possible to grow succulents, using a drier,sandier medium, but we didn’t go into that too much.
Number four: The Stuff
You can purchase dried, decorative mosses such as sheet or reindeer moss. Reindeer moss (which I think is actually a lichen) also comes dyed.The sheet moss can also be used between soil & rock layers to prevent erosion. Aquarium gravel comes in interesting colors.You can use glass pebbles,small stones or sand.You can add little bridges or other items, many specially made for terrariums but no doubt cheaper bought as toys. Try using Fimo to make your own figures, like the Zombies one customer created!
Number five: The Design
LOTS of flexibility here! A general principle might be to keep it to a few plants, as there isn’t much room and you don’t want the terrarium to look too cluttered. Also,the plants should not touch the sides.
Cover rocks & fill space with living moss.
Number six: Caring for Fairy Land
Don’t over water. A mister is a good way to direct moisture in a tight space.Mist plants individually,as their needs for water may be different. If your water contains chlorine, use distilled water.
Since soil-less mixes have few nutrients,and the soil layer is shallow,you will have to fertilize occasionally. On the other hand, you want your plants to remain dwarfed, so fertilize sparingly, perhaps with orchid or houseplant fertilizer watered down.
Terrariums require a fair amount of attention, being in an enclosed space with limited resources. Your plants may need regular clipping to keep them small.
There are a number of books on the subject available. Also check out an article in the master gardeners blog on the same topic. For myself,I’m inspired to be on the lookout for containers this winter, so maybe I’ll be on the hunt in my woods come spring!