A Guide to Terrariums

If you’re looking to add plants to your home without having to worry about all of the care and admin that can come with trying to keep them alive and thriving, terrariums are a great option.

In recent years terrariums have grown in popularity, primarily due to their low-maintenance care needs that can see them live quite happily with little intervention.

They’re also incredibly versatile, with a whole host of plant types able to be incorporated into terrariums.

In this article, we’ll provide you with a comprehensive guide to terrariums, including how to make a terrarium and the type of plants you can include inside them.

What is a terrarium?

Let’s begin by looking at what is a terrarium.

Simply put, a terrarium is a self-sustaining ecosystem that can contain plants of all types.

Terrariums come in two distinct forms as follows:

Closed terrariums: The classic terrarium type. This is a miniature ecosystem that is usually sealed inside a tank or dome.

Open terrariums: a more modern terrarium type that still contains self-sufficient plants but with the top or one of the sides open.

While both types have their benefits, closed terrariums are more common and practical. This is because they require very little maintenance due to their self-sufficient nature.

Terrariums are ideal for people who love the idea of having plants in their home, but either don’t have the space, live in an urban environment where it is impractical or simply don’t have the time or desire to spend lots of time watering or caring for plants.

Many terrarium plants are exotic or tropical in nature, and this is largely because these types of plants do better in terrarium environments where it is more humid and less water is available.

Closed terrariums utilise the warmth of the sun to create moist, warm environments within the glass casing that then causes evaporation to occur. As there is nowhere for the evaporated water to escape, it builds up on the glass before dripping back down onto the plants and soil- just like rainfall in the natural world.

Most terrariums can live for many years, requiring only a little intervention over time.

In fact, some terrariums have been known to live for decades with no human help at all. Undoubtedly the best example of this comes from the scientist David Latimer. He started growing his terrarium in 1960 and 12 years later, in 1972, stopped watering it. – As of 2023, the terrarium remains alive and thriving!

How To Make A Terrarium

A terrarium is a bit like an aquarium for plants, and typically looks like a garden in microcosm.

They’re fairly easy to make yourself but it’s important to replicate the natural environment of the plants you’re including to the best of your ability.

For instance, succulents and cacti that usually have lots of air prefer open terrariums, whereas a closed environment is normally best for ferns, ivies and other plants that thrive in humidity.

No matter what type of terrarium you’re opting for, there are a few key things you’re going to require.

This includes:

A clear, glass container: You can be really creative with the type of container you choose. Fish bowls, cookie jars, vases and most types of glassware that come with broad bottoms are appropriate.
Rocks: You’ll need a large quantity of marble-sized rocks or pebbles to cover the bottom of your glass container.
Potting soil: Make sure the soil you use has been sterilized. You can find this in most garden centres and shops.
Activated charcoal: Again, this can be found in garden centres. This is important as it prevents the growth of fungi and helps filter water.
Plants- The highlight of every terrarium, of course, you’re going to need plants. Feel free to choose plants in shapes, colours and textures that are most attractive to you. It’s worth going for miniature options that will not outgrow their container.

In addition to the list above, there are several optional extras you can include in your terrarium. This includes moss and decorative features like pine cones, shells or ceramic animals.

How To Choose The Right Plants For A Terrarium

Now comes the fun part.

Choosing the plants for your terrarium is always an enjoyable experience, but there are a few things you should consider before making a purchase.

First, as mentioned above, think carefully about the size of the plant you’re buying. Assess the size of your container and the growing potential of the plant. Opting for miniature plants is always a good way of ensuring you do not need to replace the container in a few months time. Ferns and mosses are great in this regard as they tend to remain dwarfed in size.

Naturally, if you’ve chosen a closed terrarium, this will be more appealing for plants that thrive in hot and humid conditions. With this in mind, be sure to browse the appropriate options online or by seeking advice at your local garden centre.

Luckily, we’ve previously written a blog on the best type of plants for terrariums that you can check out here.

Maintenance For A Terrarium

While their low-maintenance nature is one of the biggest benefits of a terrarium, there are still a few things you can do to ensure it remains in the best condition.

This includes the following:

Watering Your Terrarium

Terrarium plants do not require anywhere near as much water as conventional house plants, however, you should still provide it with some additional moisture from time to time.

Closely monitor your terrarium, as there are few obvious signs that it needs water. First, if the soil turns light brown it is probably a sign your plants could do with a drink.

As well as this, your terrarium should always have signs of condensation on the glass. If condensation is absent, then be sure to top up its moisture.

The best way to add water to a terrarium is by using a spray bottle and spraying the edges of the glass in a circular motion. When the soil begins changing to a darker brown and condensation reappears, you’ll know it’s had an appropriate amount.

Providing Light For Your Terrarium

Indirect light is the way to go for terrariums, so we recommend placing them near north or east facing windows. This will help them get good access to indirect light that is still bright, which is usually the type of conditions terrarium plants are used to in their natural environment.

If this isn’t an option for you, south and west windows can still work as long as the light is indirect.

Other Ways To Care For Your Terrarium

Water and light are the two main factors for terrariums but it’s also a good idea to do the following:

Remove brown or yellow leaves
Trim leaves that are overgrowing
Keep an eye out for pests and insects that could harm your plants (particularly for open terrariums).