Terrariums are very popular for a number of reasons. They are lush and tropical, are a fun way to create miniature landscapes, make for beautiful decorations, are easy to care for, and there are countless ways to get creative with them! Terrariums are really the perfect craft for any plant lovers looking to incorporate plants of all kinds into miniature landscape creations of your own.
What Is a Terrarium?
Terrariums are miniature gardens that are planted in glass containers that are partially enclosed or fully enclosed. These miniature gardens are often fully functioning, self-sustaining ecosystems, meaning that they require very little care or maintenance. There are two different types of terrariums, and the care your terrarium requires will depend somewhat on the type of terrarium you create.
What Are Closed Terrariums?
Closed terrariums are the original type of terrarium which were actually first called Wardian cases. Some of these can still be found today and they look more like a miniature greenhouse or house-shaped glass container with a small door on the top. Closed terrariums evolved from this and now include any glass container that is fully enclosed or can be sealed. Closed terrariums can be entirely self-sustaining, as the plants water themselves through the processes of transpiration and condensation. Some closed containers also include isopods, which contribute to the self-sustaining qualities of closed terrariums. Isopods eat any dead or decaying plant material and introduce nutrients back into the soil in the form of their defecations. The art of creating entirely self-sufficient closed terrariums is not an exact science, though through trial and error, it can be done. The oldest recorded closed terrarium is 53 years old and has remained entirely self-sustaining for the entirety of those 53 years!
What Are Open Terrariums?
Open terrariums are a more modernized version of closed terrariums and use containers that are only partially enclosed. These containers are often round glass containers that are open at the top or have an opening at the side of the container. A wide variety of different terrarium plants can be used in these types of terrariums including tropical plants and desert plants. Sometimes open terrariums are also referred to as arid climate containers due to the fact that they are not sealed off and are exposed to conditions outside of their container. This exposure actually enables certain plants that are more suited to arid environments to be planted in them such as cacti and succulents. Also because of this exposure, open terrariums do require slightly more care than closed terrariums and are not entirely self-sufficient.
How To Build a Terrarium
Select Your Container
The first step for how to build a terrarium is to select your container. The container you choose will depend on if you are wanting to create a closed or an open terrarium. Pretty much any container will work for either type of terrarium, you will just want to make sure that your terrarium has a lid or a way to seal it if you intend to create a closed terrarium. Some examples of containers that could be used include but are not limited to jars, bottles, fish tanks, glass bowls, vases, recycled candle containers, and nearly any other type of clear glass container.
Select Your Plants
Now it is time to select your plants. It will be important to select plants that have similar growing requirements. For example, planting a succulent with a tropical plant is not a good idea because the two plants have vastly different care requirements, and one or both will likely end up dying because they will not be getting the care they need. So, decide if you want a tropical terrarium or an arid terrarium. If you are doing a closed terrarium, it is best to select tropical plants that enjoy high humidity. Arid desert plants such as cacti and succulents will grow best in open terrariums. Tropical plants will grow well in open containers as well, they just may need to be watered or misted more often.
Select Your Planting Medium
The next step in how to make a terrarium is selecting your planting medium. The soil you choose to use in your terrarium will depend on the type of plants you selected. Desert scapes will require a more sandy, rocky soil, while tropical plants will grow best in regular potting soil, Sphagnum moss, coco coir, or something similar. So, do your best to pick a planting medium that will suit the plants you selected best. If you need help knowing what kind of soil to choose or how to create the right soil mixture, check out our blog on How to Amend Soil for Houseplants or contact us! We are more than happy to help curate the perfect soil to help your plants thrive. You will also want to be sure to pick up some pumice, lava rock, or some sort of bottom layer for your terrarium. We will go over why this will be important below!
Pick Out Some Decorations
One of the fun things about terrariums is that you can select more than just plants! There are so many fun ideas for terrarium decorations from fairy garden decorations to glass figurines to crystals, decorative rocks, pieces of wood, and more! This is one of the most fun parts where you get to pick out anything you want to set your terrarium apart and make it uniquely yours. One suggestion though is to stay away from things that are plastic, rubber, or anything else that could decay or leach chemicals into your miniature landscape.
Assemble Your Terrarium
The last step involves putting it all together! Just remember with this step to have fun and don't get too worried or overwhelmed by where to put things. You can always rearrange things as you go to make your terrarium just the way you want it to be. Here are the steps you should take when assembling your terrarium:
Add a Drainage Layer. You will first want to start off by creating your drainage layer. This layer will collect any excess water, helping to avoid the soil in your terrarium from staying too wet. The most common material you can use for this layer is pumice, though you can also use lava rock or gravel. This layer should be around an inch deep. PRO TIP # 1: If you are using plants that are more sensitive to root rot, placing a coffee filter between your drainage layer and your layer of soil will keep the roots of your plants from growing into the drainage layer where they may be exposed to more moisture than they can handle. PRO TIP # 2: Mixing some charcoal into your drainage layer will help to purify the water that collects there, helping to avoid any water that does collect there from becoming gross or murky.
Add Your Soil. Next, you will want to choose your substrate/planting medium and add approximately a 1-2 inch layer on top of your drainage layer. In total, the drainage layer and substrate should really only take up approximately 1/3 of your container. Your plants will fill the rest of the space!
Add Your Plants. Now for the fun part! Take the plants you have chosen for your terrarium and place them in your container. You can use tools such as spoons, butterknives, etc. to dig little holes where you want each plant to reside. Remove your plants from their containers, loosen the roots and existing soil if necessary, and place them in their position. Then gently pack in the soil around the base of the plants, adding more soil if necessary.
Add a Decorative Top Layer. If you are planting an arid landscape, you can apply a top layer of gravel or something more decorative. Some more tropical landscapes look marvelous with some moss or other decorative rocks. A top layer is not required but can add to the aesthetic of your terrarium.
Add any Other Decorations or Figurines. There is really no exact guide when it comes to this step, so get creative! You can add larger decorative rocks, glass figurines, chunks of wood, or anything else that comes to mind. We do recommend staying away from plastic or rubber objects that could leech chemicals into the environment or begin to rot or mold, especially with closed terrariums.
Water Your Terrarium. Now that everything is assembled, give your terrarium a light misting. Arid terrariums with cacti and succulents will need less watering than a terrarium that includes more tropical species. The soil should be moist, but you never want to water so much that the drainage layer is full and causing the soil to become oversaturated. Just remember, when it comes to watering, it is always much easier to add more water than it is to take away water!
How To Care for a Terrarium
Caring for terrariums is really quite simple. The key to properly caring for your terrarium plants is being familiar with the types of plants you chose for your terrarium and knowing the specific needs of those plants. Keeping that in mind, let's talk about how to care for a terrarium.
How to Water a Terrarium
Terrariums generally do not need to be watered as frequently as other houseplants. This is because they do not have a drainage hole and the semi-to-fully enclosed space does not allow water to evaporate as quickly as it might with your other houseplants.
Watering Open Terrariums: How often you water open terrariums depends on the plants you choose. If you have selected desert plants such as cacti and succulents, watering approximately once a month is ideal. Tropical terrariums may need to be watered more often depending on the light they receive. Open tropical terrariums in bright light can be watered approximately every 2 weeks, and open tropical terrariums in medium light can generally be watered every 3 weeks. However, it is always best to observe the drainage layer at the bottom of your container before watering your terrarium. You never want this layer to be fully saturated, as this means that your soil is likely oversaturated. If you notice water or condensation in the drainage layer of your terrarium, there is no need to water. Wait for that layer to dry out before watering again. Remember, it is easy to add more water and nearly impossible to take away water without having to start over with your terrarium entirely.
Watering Closed Terrariums: Closed terrariums may only need to be watered once in their lifetime. If closed terrariums are properly sealed, they will be rather self-sufficient and will water themselves through the processes of transpiration and condensation. Basically, the plants in your closed terrarium will soak up the water that was initially introduced to the environment. This water will then be released through the leaves of the plant (transpiration), which will then collect on the walls of your container (condensation), eventually dripping back down into the soil where it is able to be soaked up again by the plants. Some closed terrariums have lids but are not permanently sealed or entirely leak-proof. If this is the case, your terrarium may need some water introduced to it, but this need will be very infrequent. If you have a closed terrarium that does not have a permanently sealed lid, be aware of the condensation that collects on the walls of your container. Healthy closed terrariums should only experience condensation collecting on the glass for a portion of the day. If you notice the condensation does not dissipate, open the lid of the terrarium to let it air out slightly. Conversely, if you never notice any condensation buildup at all, you may consider adding some moisture to the terrarium.
Light Requirements for Terrariums
Both open and closed terrariums require bright, indirect light. They should never be placed in direct sun as this will heat up the inside of the container very quickly and can cause severe damage to your plants. Even with open terrariums, the curved glass can act as a magnifying glass, causing concentrated heat buildup in your terrarium. So, always keep your terrariums out of direct sunlight.
Clean Up Plant Debris
Cleaning up dead or dying leaves is an important aspect of caring for your terrarium plants. Not only does this keep your terrarium looking nice and tidy, but it also will help avoid dead or dying leaves from beginning to rot or mold. Cleaning up plant debris in open containers can be done easily with miniature gardening tools, tweezers, scissors, or any other household items that help you navigate your miniature landscape. With closed containers, you can remove the lid periodically to remove plant debris or you can introduce your very own cleanup crew. Isopods are little insect-like creatures that are actually a type of crustacean. They feed on decaying matter and can live in a permanently sealed terrarium, contributing to the self-sustaining properties of the terrarium. The isopods eat the dead plant matter, keeping the terrarium clean and tidy, and then they defecate, adding essential nutrients back into the soil, keeping your terrarium plants happy and healthy.
Trim Your Plants Periodically
If you notice your terrarium plants beginning to outgrow the container or leaves beginning to get smashed up against the walls of your container, it may be time to trim them back. Leaves touching the walls of your container can cause them to become unhealthy and may not provide the look you were aiming to achieve. So, simply pull out your sterilized scissors or miniature gardening tools and snip off overgrown leaves as you see fit, being careful to not trim the plant back too much. Knowing the individual plants you chose for your terrarium will be important as each plant may need to be pruned differently. So, do your research or reach out to us for assistance!
How To Make a Terrarium
If you have any further questions or need assistance building a terrarium of your own, we are always happy to help! You can reach out to us via email, phone, or by coming into the store. We have all the materials you need to create a terrarium and our knowledgeable staff will be able to answer any questions you may have. You can also shop for terrarium kits and supplies in our online store or check out our houseplant selection! Happy planting, everyone!