Lockdown terrariums
How to create your very own lockdown terrarium
The first ‘terrariums’ (or terraria) were Wardian cases — glass enclosures for exotic plants, which allowed them to be transported around the world on the decks of ships, safe from the salt spray which would have killed them.
Terrariums are now a popular way of keeping houseplants, providing humid conditions which are otherwise hard to achieve in the home.
What you’ll need
By using what you already have in your home you can make your very own ‘lockdown terrarium’. You’ll need a glass container with a lid (such as an old jam jar), some compost, a little gravel and some plants or moss.
Start with a nice clean jar or bottle. A jar is easier, but a bottle looks more impressive as people will wonder how you got everything inside!
Unless you can fit your hand inside the container, you’ll need to make some tools. You can be really creative with this and use whatever you can find at home, but here are some suggestions:
- A funnel to get gravel and compost through the neck of a bottle: a piece of a flowerpot or other plastic packaging, folded into a cone shape, works well for this
- A stick or pencil for making plant holes
- Something for tamping down the soil around the plants –e.g. piece of wire or a knitting needle, with a large button glued to the end
- Cleaning and maintenance tools — some compost always sticks to the inside of the glass. You can clean it off using a piece of washing up sponge glued to the end of a wire, so it can be bent to just the right angle. For ongoing maintenance, a skewer is useful for picking out dead leaves, and a craft knife blade taped to a stick can be used for pruning.
Building your terrarium
Step one | Gravel
First add a layer of gravel to cover the base — the depth can vary but will typically be 1–3cm depending on the size and shape of the container.
Step two | Compost
Then add a layer of compost. Again, the depth isn’t critical, but most plants you’re likely to use in your terrarium would like at least 5cm depth for their roots. You can make it deeper if you have space. If you’re only using moss in your terrarium a shallower layer will be fine.
Step three | Choose your plants
Now for the most exciting bit — planting your miniature landscape! Suitable plants for terrariums are those which tolerate warmth, low light and high humidity. Typically these are found on the forest floor, where conditions are damp and shady.
Suitable species include houseplants such as Fittonia; Chlorophytum (spider plant); Ficus pumila; Peperomia; Hedera (ivy) and small ferns.
If you don’t have suitable houseplants, you could try collecting different types of moss from your garden to make a mossy landscape in your terrarium. When collecting your moss, think about the conditions you find it in and whether these exist in your terrarium; moss growing on the surface of damp soil will be most suitable, while moss growing on dry stone is less likely to thrive.
Step four | Planting
Use your tools to scrape a hole big enough for your plant’s roots, then drop it in, scrape the soil back into position and gently tamp it down around the plant. If you’re using a bottle with a narrow neck you may need to use a couple of sticks as if they’re chopsticks, to get the plant in and manoeuvre it into place.
If your container is big enough, use two or three different plants to create interest — but don’t overcrowd them or they’ll be prone to fungal problems. They shouldn’t press against each other or the walls of the container.
Step five | Watering
When you’re happy with your landscaping, clean the inside of the glass if necessary, and give your terrarium a drink. They need less water than you might expect — around 5 squirts from a spray bottle for a terrarium of about 1 litre. Remember you can always add a bit more water later if your terrarium looks dry, but it’s hard to remove water if you start by adding too much, especially if using a narrow necked bottle.
And you’re done!
How to maintain your terrarium
The aim of a terrarium is to be almost maintenance-free, as the sealed container keeps in moisture, which cycles continuously between the plants and the air inside the terrarium. It can take a little while to balance this at first. Monitor it carefully — if the plants look dry and leaves are becoming crispy, add a little more water; if there’s a lot of condensation and leaves are dying and becoming slimy, or growing mould, leave the lid off the container for a day or two until it’s dried out a bit.
Ruth Calder
Botanical horticulturist
Oxford Botanic Garden and Arboretum
We’ve love to see your creations so please do share them with us on Twitter using the hashtag #LockdownTerrarium
Twitter: @OBGHA | Facebook: @OxfordBGA | Instagram: oxfordbga
