A terrarium is a miniature garden that is enclosed in a glass or plastic container. Terrariums can be open or closed, but closed terrariums are the most self-sustaining. In a closed terrarium, the water cycle is closed, meaning that the water that evaporates from the soil is trapped inside the container and eventually condenses back onto the leaves of the plants. This allows the terrarium to be very low-maintenance, as you only need to water it occasionally.
Choosing a container
The first step in creating a terrarium is choosing a container. Any glass or plastic container that is the right size for the plants you want to grow will work. However, there are a few things to keep in mind when choosing a container.
- The container should be clear so that you can enjoy the plants inside.
- The container should have a lid that can be tightly sealed. This will help to keep the water cycle closed.
- The container should be the right size for the plants you want to grow. If the container is too small, the plants will not have enough room to grow. If the container is too large, the plants may not get enough water.
Choosing plants
The next step is choosing plants for your terrarium. When choosing plants, there are a few things to keep in mind.
- The plants should all have similar water and light requirements. This will help to ensure that all of the plants in your terrarium thrive.
- The plants should be the right size for the container. If the plants are too large, they will outgrow the container quickly.
- The plants should be attractive and complement each other.
Some good choices for closed terrariums include:
- Moss
- Ferns
- Air plants
- Tropical plants
Checkout our collection of Tropical Terrarium Plants, which has been selected for their ability to survive in a high humidity, low light environment and stays relatively small.
Creating the terrarium
Once you have chosen a container and plants, it is time to create your terrarium.
- Start by lining the bottom of the container with a layer of gravel or pebbles. This will help to improve drainage. This is where all the excess water will accumulate, so when watering the terrarium, make sure you don't water too much that this layer gets fully soaked with water.
- You can also add a layer of activated charcoal to the drainage layer. Activated charcoal helps to filter the water and prevent the growth of mold. This step is optional, we have had great success with terrariums without activated charcoal.
- It is good to add a barrier between the drainage layer and the soil layer so that the soil does not get into the drainage layer. You can use a piece of flexible net, clothe or use a plastic bag with tiny holes cut in it with a needle so that the water can freely pass through it to the bottom but the soil stays on top of it.
- Add a layer of potting mix. The potting mix should be specifically designed for terrariums. It should be a well draining soil mix that retains moisture well. You can checkout our blog post about how to create a terrarium soil mix.
- Plant the plants in the potting mix. Be sure to leave enough space between the plants so that they have room to grow.
- Optional: add a layer of moss or other ground cover. This will help to keep the soil moist and prevent it from drying out.
- Water the terrarium thoroughly, but be careful not to overwater. If you accidently overwater your terrarium, you can tilt the terrarium and use a piece of clothe to wick the water and empty it out. Or you can just leave the container open until it dries up.
- Seal the terrarium with the lid.
Caring for your terrarium
Once your terrarium is created, it is important to care for it properly.
- Water the terrarium as needed. The frequency of watering will depend on the type of plants you have and the size of the terrarium.
- Place the terrarium in a spot that receives bright, indirect sunlight.
- Optionally you can fertilize the plants every few months with a diluted fertilizer solution.
These are the basic things you need to know, you can checkout our care guides section on taking care of closed terrariums for more information.
Creating a self-sustaining closed ecosystem terrarium is a fun and rewarding project. With a little planning and care, you can create a beautiful and low-maintenance addition to your home.