How to make a terrarium
The base layers
- Cover the base of the glass container with pebbles, at a depth of about 1 or 2 inches.
- this is the drainage layer, to hold any excess water so that your plants do not get waterlogged.
- Next, cover the top of the layer of pebbles with the activated carbon. You do not need too thick a layer here, just make sure it covers the pebbles until you can no longer see any poking through.
- this is to help purify and clean the terrarium and prevent bad smells and mould.
- The next layer will be of sphagnum moss. Spread this out over the activated carbon to completely cover it.
- this layer helps to absorb any excess water, as well as retaining moisture in the terrarium. It also acts as a protective barrier from the soil to the bottom layers.
- Now you want to pour your soil over the sphagnum moss. This will be where you plant the plants and/or live mosses. Make sure there’s a 3-4 inch thick layer of soil, (or as much as you need, use your judgement here!) and use your fingers to break down any bigger bits and smooth the soil down. If it is dry, water it very lightly.
- Make a little hole big enough to accommodate your plant with your fingers or some other tool if the opening of the container is too small (such as a spoon or chopsticks). If the plant is in a pot, you can squeeze it out gently, but make sure the soil is damp before attempting this!
*If you have received your plant bare-rooted (i.e. NOT in a pot) do not do this next step.*
If needed, break down the root ball gently by squeezing it with your fingers and removing the excess soil. Squish the root ball (gently!) so that it will fit into the terrarium and the little hole you just made for it. Be careful not to damage any of the roots.
- Making sure that any leaves are a good distance away from the glass, place the root ball into the soil, then place some more soil around it. Pat the soil down around it to compact it, and add more as you see fit.
- If you have any more plants or some pillow moss, repeat steps 5-6. You can break off pieces from the pillow moss if it is too big and plant them separately. If you have other types of moss, you can just place them on top of the soil and pat them down, watering lightly.
- Place your decorative accessories in your terrarium, however you like. Be careful when introducing items that might be dangerous for your terrarium, such as sticks from your garden - these need to be cleaned and sterilised to make sure there aren’t any bugs or infections that could damage your plants.
Looking after your terrarium
- Water your terrarium. It doesn’t need too much water, but make sure the soil is moist. Don’t worry if you over-do it slightly - your drainage layers will collect any excess water. Tip for succulents, cacti and air plants: they shouldn't be in a lidded terrarium. Succulents and cacti should be watered when the soil has dried out, and the soil should not be too wet. Air plants should be treated to a weekly misting and monthly soak, and should remain in a well-ventilated and open area.
- If your terrarium has a lid, close it. You will not need to water it very often, but make sure you keep an eye on it. If too much condensation starts to collect on the glass of the terrarium, open the lid and allow some air in for a few hours. Similarly, if it’s starting to look a little dry, water it a little more.
- If you see any mould, rot or dying leaves, make sure you remove them immediately.
- Some plants may require an occasional trimming - use your judgement. If it looks like it’s growing too long, trim down excess stems and leaves. This will keep your plant alive and thriving, as well as making sure it doesn’t take over your terrarium.
- Keep your terrarium in a space where it will receive indirect sunlight (direct sunlight might burn your plants through the glass) and protected from any cold winds etc.
- Optional: Submit a picture of your completed terrarium so I can post it on the website www.ukterrariums.co.uk :)