Anytime you build a terrarium, you’re always going to need a certain set of materials and tools to get the job done. So what are they?
Every terrarium consists of five components: the container, the drainage layer, a separation material, a substrate, and plants. Decorations, activated charcoal, and springtails are optional add-ons. While you can order these online, you can also find many of these materials at home or in your backyard. Some useful tools to help out with putting the materials together include: tweezers, scissors, a spray bottle, and a funnel or a scoop.
In this article, I’ll go into all the details as to what each of those tools and components are and how you can choose the right ones to pair up with your next terrarium.
Table of Contents
Terrarium container ideas
The first component that will make up your terrarium is the container. You can kind of think about it as the skeletal structure of your terrarium. The size and shape will heavily influence what kind of design your terrarium will follow overall.
At the same time, you have an abundance of options available to you. There aren’t too many requirements for terrarium containers other than that it is transparent and gives your plants enough space. For the most part, that means plastic and glass.
The advantage of that is that you can use pretty much anything you want, including some leftover containers you have at home that you might have been planning to recycle anyways.
The downside is it can be overwhelming to think about the endless options available to you if you don’t know where to start.
To help you out with that, here’s some ideas for terrarium containers that you can buy online or at a local department store:
- Glass jug
- Wardian case
- Light bulb
- Erlenmeyer flask
- Plastic storage bin
- Fish tank/aquarium
- Glass vase
Here’s a list of ideas for low cost DIY containers that you might find at home:
- Empty jam jar
- Wine bottle
- Perfume bottles
- Plastic takeout food containers
If you’re deciding between several different container options, my recommendation is to go with a larger terrarium if you can. That’s going to make it a lot easier to handle your plants with your hands.
A larger container will also help to minimize the effects of over or underwatering. The larger size serves as a buffer because there’s just more space for the water and humidity levels to even themselves out. That means it’s going to be a lot more forgiving if you’re making any mistakes.
If you’re more interested in the pure enjoyment of building terrariums, I would recommend getting a plastic bin. That’s going to give you plenty of space at a reasonable price.
If you’re building a terrarium because you want something that looks nice, I would say go with a glass container. Generally, glass is going to be more aesthetically pleasing than a plastic container.
For more recommendations, check out my recommended terrarium containers here.
What goes in the bottom of a terrarium?
At the bottom of the terrarium, you will be adding some structure to create the drainage layer. For most terrariums, rocks or sand will be just fine to accomplish that, but there are also other options that you can choose from.
The purpose of the drainage layer is to create empty space for water to drain out of the substrate layer. It prevents stagnant water from suffocating your plant roots and causing root rot. It’s this empty space where excess water congregates to later evaporate and recondense inside of your terrarium.
When you’re choosing which material you should use, there’s a few things you should look for:
- Doesn’t dissolve or fall apart in water
- Won’t collapse easily with a little added weight
- Creates openings for water to pass through
If your material matches those characteristics, you should be good to use it. But if you’re looking for some ideas to get your gears turning, I put together a short list that you can reference here:
- Egg crate
- Filter/foam material
On top of the drainage layer, you will also need to add some material to keep the substrate and your plant roots out of the drainage layer. At the same time, you’ll still want water to pass through this separation material.
What this means is that you should be looking for something that is either porous or has some holes to allow water to flow through, but that doesn’t have openings so large that roots can sneak through. If you have to, you can poke some holes of your own to create those openings.
In my opinion, the perfect material for this is a window screen mesh. The closer you can get to something like that, the better. However, there are still plenty of other options out there that will work just fine.
Here’s a list of separation materials that you can look through for some ideas:
- Synthetic window screen mesh
- Thin piece of plastic
- Weed blocker
- Sphagnum moss
By the way, I wrote a huge blog post on this listing out all the pros and cons of each of those materials as well as pricing comparisons that you can check out here to learn more about drainage layer materials.
What is a terrarium substrate and which substrate is the best?
A terrarium substrate is essentially the soil that your plants are going to grow in. Potting mix is probably the first thing that comes to mind, but there are also other options out there that will also function as the substrate.
What you should look for with a substrate is that it provides sufficient nutrients for your plants and ideally retains water well without clumping together/compacting.
Before picking any substrate, double check to see if it will provide enough nutrients. Coir for example, doesn’t provide any nutrients at all and will have to be supplemented with some nutrients.
Here’s a list of some substrates that have been used successfully:
- Potting mix
- Coir + supplement
- Soil from your backyard
- Sphagnum moss
- Aquarium soil
If you’re looking to add some supplements to your substrate to increase the nutritional content, here are some things that you can consider:
- Earthworm castings
- Leaf litter
As for the best substrate, there is no “best” singular one size fits all solution. It largely depends on what type of plants you have and what preference they have for a substrate and the substrates nutritional content.
Carnivorous plants for example, will not tolerate high nutritional content in the substrate since they’ve adapted to growing in nutrient poor conditions.
I also wouldn’t recommend adding fertilizer to the substrate. Your plants might grow too big too fast and end up outgrowing the size of your container.
You can also consider mixing different types of substrates together to get an intermediate between their different properties. For example, you could mix coir with some potting mix and leaf litter to get a substrate that retains water pretty well while having a decent amount of nutritional content.
If you’re still not sure and you want something that “just works”, I would say potting mix has a high chance of success for most terrariums. It’s also pretty cheap and available at most stores that sell gardening supplies.
What kind of plants do you put in a terrarium?
Obviously, you’re going to have a lot of options for what plants can be added to a terrarium. But that doesn’t necessarily mean that you can put any plant into any terrarium.
The types of plants that will survive in a terrarium largely depend on what type of terrarium you’re making: an open or closed terrarium.
An open terrarium (a container without a lid) will be best suited for plants that prefer dry, arid, full sun conditions. Succulents are a great example of this.
A closed terrarium on the other hand, will be best suited for plants that enjoy high humidity, indirect light conditions. Moss and ferns are standard examples of that.
If you’re not sure which type of terrarium you should make, I explain that in detail in this article.
One simple way you can decide is by thinking about whether you want something that is more like a traditional houseplant or want to make a mini ecosystem in a container. If it’s the latter, you should go for a closed terrarium. That’s what most people think of when they hear the word “terrarium”.
You could also just decide based on what container you have available at home. There’s really no right or wrong answer. If you want, you can go ahead and make one of both, no one’s stopping you.
Once you figure out if you’re going to use an open or closed terrarium, that pretty much cuts the number of plant choices you have in half and it will make it a little easier to choose your plants.
Here are some plants that would work for a closed terrarium:
- Creeping fig
Here are some plants that would do great in an open terrarium:
- Air plants
If you’re looking for some more ideas, check out my other plant recommendations here. I list some plants that have a good chance of doing well in both open and closed terrariums.
What tools do you need for a terrarium?
When building a terrarium, tools can certainly be a great asset to have. They can make your life a lot easier when performing maintenance or setting up your terrarium. But they are by no means a requirement for building a terrarium.
As long as you can access your terrarium and handle your plants with your bare hands, you shouldn’t have to go out and buy tools to build a terrarium.
The one scenario I can imagine where tools might be required is if you are working with a container with a small opening. This type of container will require you to use some type of tweezer to handle your plants within the terrarium.
But regardless of whether or not tools are required, they can still be well worth your investment just from the headache that they might save you later on.
Here’s a list of tools that I think will give you a lot of bang for your buck:
- Tweezers or chopsticks
- Spray bottle
Probably the tools that you’ll get the most use out of are the tweezers and the spray bottle.
Tweezers are going to make it a lot easier to navigate those tight spaces and help you place your plants exactly where you want them. That’s going to be a necessity if you’re working with a container that has an unusual shape, tight corners, or a narrow opening.
It also reduces the chance of you bending and deforming your plants compared to handling them with your bare hands. That’s going to be very helpful if you’re trying to create a work of art or want to be very delicate with your plants.
I also recommend getting a spray bottle if you can. Misting your terrarium is going to help a lot with evenly dispersing the water when watering your terrarium. Otherwise, you’re going to have to be very careful when pouring water in from a cup to make sure that there’s no localized spots that are getting overwatered.
Having a spray bottle is going to reduce the chance that you might get mold growth by limiting the chance of creating small over-watered areas in your terrarium. It also helps to get the water onto your plant leaves rather than having it all land in droplets in the soil.
Scissors might come in handy once in a while when you have to prune your plants. That’s going to be helpful when your plants are growing a little bit too large for your container. It’s also going to be necessary if you want to touch up your terrarium to get it looking fresh again, kind of like mowing your lawn.
If you don’t have any tools to begin with, I recommend starting with a terrarium tool kit. The toolkit should come with a lot of the tools that I recommend all for a much lower price than buying each tool individually.
The only downside of a tool kit is the individual tool quality might not be as great as buying the tool on its own. If your tools are just going to fall apart in a few months or be a little bit frustrating to work with, it might just be worth spending a little bit more money upfront for something of higher quality.
Terrarium decoration ideas other than more plants
The last set of materials that you might want to consider for a terrarium is decorations. These are by no means necessary for a terrarium, but they can be a nice touch if you want to add some flair to your terrarium.
Here’s a list of decoration ideas that you can try out:
- Figurines (great for turning your terrarium into a little world)
- Small models
- Pine cones
- Resin (great for creating the illusion of a body of water)
- Glitter (can be used to create a snow-like effect)
Another way you might be able to find more ideas is to simply browse cool terrariums that you see online and reverse engineer what they did. With a little bit of resourcefulness, you might come out with a few ideas of your own in the exploratory process.
If you’re interested in more ideas, I got a lot of the bullet points in that list from my other blog posts that you can check out here.
Where you can buy terrarium supplies
If you’re looking to buy terrarium supplies, there’s a few places you can get them.
Here’s a list of sites that you can get terrarium supplies online:
- Josh’s frogs
If you would rather go in person to get your supplies, I can think of a few places:
- Home depot
- A local plant nursery
- A local co-op store
- A local farmer’s market
From my experience, you’ll probably have better chances shopping online for terrarium materials. You’ll get more listings for more niche tools and materials like bundles of moss, unique containers, and terrarium specific materials.
The big department stores usually are more geared towards gardening in general and might not have that rare wardian case you’re looking for. Although, you can still make it work if you’re not looking to do anything fancy, like just shopping for some potting mix.
If you are looking for something unique or special in your local area, you might have good chances of finding something unique and interesting at your local plant nursery. Certain co-op stores might also offer something more along the lines of a hipster’s tastes.
Do you need springtails in a terrarium?
Springtails are a great addition to any terrarium, but they aren’t absolutely necessary.
Springtails are like tiny little janitors that live in your terrarium. They are small whitish grey insects that eat up mold and decaying organic material, basically all the stuff that you don’t want to see in your terrarium.
Springtails add a lot of value to a terrarium by controlling mold growth and completing the cycle of life within the terrarium.
However, if you don’t want to or are not able to add springtails to your terrarium, you can still have pretty good chances of having a thriving terrarium. In my first two terrariums, I didn’t add any springtails at all and they seem to be doing just fine so far. I suspect you’ll probably find similar results without springtails.
If you want to learn more about springtails, check out this article where I go more in depth on how to culture your own springtails for a terrarium.
Do you need charcoal for a terrarium?
No, you don’t need charcoal for a terrarium, but it might help a little bit with purifying your water from toxins and reducing odors. Even if you decide to go without charcoal, you still have pretty good chances of being successful with your terrarium.
So there’s a whole debate about whether or not charcoal is necessary for terrariums.
Some people believe that activated charcoal isn’t worth the trouble because it’s just going to run out after a certain amount of time. Others (and most terrarium building tutorials you’ll read about) recommend adding charcoal to your terrarium for the reasons I listed above.
The truth is, both sides have some element of truth to them. Activated carbon does run out eventually because over time the pores that chemicals can bind to on the charcoal will all be occupied by things that it has already binded to. That’s just a fact of nature with any adsorption material. That’s why all carbon filters have to be changed out every so often.
At the same time, activated carbon is effective at binding to chemicals and toxins. It’s used in industry all the time for all sorts of purification processes.
The real question is how long will activated charcoal last in a terrarium? Unfortunately, there hasn’t been anyone who’s done a scientific study on this as far as I can tell. It’s very difficult to quantify because there are too many possible variables to account for, such as what plants you are using, the type of substrate you are using, temperature, water levels, humidity, and quantity of activated charcoal being used.
In my opinion, I suspect you might get some use out of activated charcoal for about 1 or 2 years, after which it might not be as effective. That’s loosely based on how often you have to change aquarium filters (usually once every month).
All it comes down to is a matter of personal preference and maybe how paranoid you are about “toxins” in your terrarium. In my personal experience, I’ve built my terrariums without using activated charcoal and I haven’t had any problems so far. But it definitely doesn’t hurt to err on the side of caution and throw some activated charcoal in there.
Just be sure to avoid barbecue briquettes. Those have chemical additives that will probably be harmful to your plants. That’s the only thing I would recommend against.
If you want more details and the full story behind the activated charcoal debate, you can check out my full blog post on this topic here.
Do you need sand in a terrarium?
Sand is not necessary for a terrarium, but it can be used either as a drainage layer material or as something you can mix with the substrate to increase drainage.
Sand can be used as a drainage layer material. There should be enough pore space to allow water to pass through without mixing too much with the substrate. Because it doesn’t really mix with the substrate too much, you could even skip out on the separation layer. Plant roots will probably not grow into the sand too much because of the lack of nutrients, maybe with a few exceptions.
The nice thing about using sand as a drainage layer is that you can get some cool designs if you use colored sands. Just stack on different colors and you’ll get colorful wavy patterns without really doing anything too special.
The only downside that I can think of is that you won’t get as much drainage compared to using something that creates more open space for drainage like rocks or egg crate. This means that a little bit of water can creep back up into the substrate from the sand. It’s not ideal, but it’s definitely not a deal breaker.
The other scenario you would want to use sand is if you want to mix a little bit of sand with a substrate to increase drainage and aerate the soil.
The sand particles break up the adhesion of soil molecules, allowing the soil to be looser and less compacted. That’s great for giving your plant roots some air to breathe.
What do terrariums need to survive?
Terrariums in general are pretty resilient (when done properly) and don’t require too much maintenance. As long as you are using the right plants for your type of terrarium (open or closed) and give it the right amounts of water, you shouldn’t run into too many issues.
However, there are certain baseline requirements that terrariums need to survive:
- Sunlight (less for closed terrariums, more for opened)
- Water (more for closed terrariums, less for opened)
- Reasonable temperatures (room temperature is fine)
If you can give your terrarium those three things, the terrarium will practically take care of itself at that point with minimal effort on your end.
If you’re really paranoid and want to scope out what could potentially go wrong with your terrarium, you can read more about that in this article.
Other than that, that’s pretty much it in terms of terrarium materials that you’ll need. If you want to learn more, feel free to check out some of the articles below or ask a question in the comments.