Hello and welcome to Natural World Facts, toady I'm here in a woodland and I'll be showing
you how to create a closed terrarium.
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A terrarium is a sealed ecosystem in a jar, which if done properly can be almost entirely
self-sustaining with its own nutrient and water cycles as the plants water themselves
through transpiration and condensation.
It works from the warmth from the sun causing moisture to evaporate from the plants and
soil, which then condenses on the cooler glass surfaces of the container. Just like rain,
the water drips back down into the soil and the process starts over.
At the same time, the soil layer provides the plants with nutrients, and those nutrients
are replenished as the plants die and decompose into the soil, giving new life.
Before you set out to find materials, you will need a large clear jar with an airtight
lid, and optionally a sheet of mesh or any kind of porous material to separate the soil
from the stone layer later on.
Once you have a jar, set out into your local park, woods, or your back garden with some
containers to collect the rest of the materials.
You will need to gather a few handfuls of small stones or pebbles and enough soil to
provide a soil layer a few inches thick.
Now you can search for plants you may want to use; moss works great as it loves damp
conditions, and can look stunning in a terrarium.
Otherwise, look for grasses and small plants such as weeds that don’t grow too large.
When collecting moss, be sure to only take small amounts where possible, as moss takes
a very long time to grow and provides vital habitats for wildlife.
The best way to gather moss is to take it from the centre of a patch, rather than the
edges, and then to brush the moss around the gap inwards to provide cover for any insects.
If you come across any isopods, or woodlice, keep these for later as they will act as a
clean-up crew in your terrarium, breaking down dead organic matter and preventing the
growth of mould which can kill your plants.
Now that I've gathered everything that I'm going to need to make this, I have my glass
jar with a lid, I have my stones and my moss and plants and any nice bits of wood that
I found that I thought would make a nice hardscape.
And I have a little box of woodlice. They will be the clean-up crew, cleaning up any
decaying wood or dead plants.
The first step will be to place a layer of rocks or small pebbles at the bottom of the
glass jar, and what this does is it creates a 'false bottom' or a drainage layer, so that
when the water filters through the soil from the plants it doesn't sit in the soil among
the roots and cause rot.
Instead it will sit in the gaps between these rocks, preventing any mould from forming.
Now that I have my false bottom in place, my layer of stones at the bottom, I would
usually put in a layer of mesh or some kind of permeable surface so that the water can
soak through but it still separates the sediment from the rocks.
I don't have any of that with me so I'm just going to put the sediment layer on top of
the rocks and hope that not too much of it falls through into this false bottom.
For sediment I'll just be using the soil that's readily available here in this forest as it's
very rich in nutrients as you can see, because of all the leaves and dead matter that falls
from above and decays, giving its nutrients to the soil.
It's also full of worms which is great for a terrarium as it will add even more nutrients
to the setup.
Gonna get a nice layer of soil in there, and to compact it down to the bottom there, I'll
be using this blunt stick just like this.
Now that I have a soil layer which is juts a few inches thick above the false bottom,
we can start adding the plants. I've collected quite a nice array of plants and hardscape
here to put into my terrarium.
I've got some fungi, some mushrooms that I found. I have some old decaying wood. And
of course I have the moss that I collected.
I also gathered this nice hard bit of wood from the forest floor. I'm going to break
this down into a smaller piece that will fit in here, then I'll start putting the plants
in around it.
I found this nice piece here which is attached to some hard wood. I think this will go very
nicely.
I have quite a large piece of moss here that I pulled from the base of a tree, so I'm just
going to separate this into smaller pieces that will be much easier to work with.
Just press it down into the soil, into the substrate, like so.
Going foraging for some nice little plants here that will go well alongside the moss.
You don't want to choose anything that can grow too big, so nothing like these ferns
around here and definitely not saplings. But grasses are excellent as they provide ground
cover and they'll grow in really well and cover up any areas of sediment.
Manoeuvre that into position. Get a nice long stick, or whatever you have available. Press
the roots down into the soil, as deep and as firm as possible.
I've gone with quite a simple design. I've just got a little bit of wood, a few mosses,
one fungus and some grass and I think that will do nicely for this one. But of course
if you've got more plants around or more choices for things that you can put in, small plants,
weeds do very well in there, then by all means put them in but I'm going to go with this.
I'd say this is done.
The next step is to add some water. It's best to do it from a spray bottle but I don't have
one with me, so it's also okay to do this.
Make sure everything is nice and watered.
You also don't want to over-water it, because when you put the lid on and seal it that water
isn't going to be able to escape and too much water can cause the plants to die and mould
to form and you don't want that.
Before we put the lid on, I'm going to do one last thing. Gonna get the tub which is
full of the isopods or woodlice that I collected. And I'm going to get them out, and place them
into the terrarium.
It's inevitable that some of the plants you put in won't adapt well to this kind of an
environment. What the woodlice will do is they will break down any of the dead plant
matter and any decaying wood and stop mould growth.
Now that we've added the false bottom, the sediment layer, the plant layer, the hardscape,
the isopods and given it a good watering, it's time to put the lid on.
And this is a closed terrarium in a jar. A self-sustaining ecosystem that you can put
on your windowsill and enjoy.
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