How To Create A Self-Sustaining Terrarium

Nick Durante
by Nick Durante
Credit: Shutterstock / Natalia Hrynovets

If you’re new to terrariums, it may seem like a daunting task to create one that thrives. Luckily, it’s easier than you think to set up a terrarium that takes care of itself. You can create a self-sustaining terrarium with careful preparation and a few simple supplies.

The best way to create a self-sustaining terrarium is to make a substrate from peat moss, potting soil, and pea gravel. You only need to use 2 ½” of substrate in many cases, but it depends on the size of the container. Pick plants that don’t grow too quickly, or else you must prune them more often.

You can cut down on maintenance if you put isopods in your terrarium to eat dead plant material. Follow along as we explore how to create a self-sustaining terrarium without spending a fortune.

What Do You Need For A Self-Sustaining Terrarium?

1. Durable Container

One of the best things about a terrarium is that you can turn a variety of containers into one. People turn everything from vintage milk jugs and vases to fish bowls into a terrarium. That doesn’t mean you should simply turn any container into a terrarium without considering its size and durability.

Carefully consider the plant layout you have in mind, and pick a container based on that. For example, you may need a big, deep container if you want to include plants with deep roots. Durability is also quite important, as you don’t want to clean up broken glass if your terrarium falls.

2. Healthy Substrate

You can lay the foundation for a vibrant, self-sustaining terrarium if you use the right substrate. While you can make a homemade substrate, you can also buy premade mixes online. Many people make substrates out of pea gravel, peat moss, and potting soil.

Peat moss helps with water retention, and that’s quite important, as terrariums rely on consistent moisture. Gravel provides a strong base, but you must be careful and not use too much. You can hinder plant growth and root systems if there’s too much gravel.

Most people get by with 2 ½” of substrate, but it varies based on the size of the tank. Moisten the substrate before you add plants, but make sure you don’t over-saturate it.

3. Add Plants

Adding plants to your terrarium is the most exciting part of the process. Air plants typically work quite well in a terrarium, as well as ferns, and peperomias. However, it’s important to consider the size of your terrarium compared to how quickly the plants will grow.

For example, you should never put a fast-growing plant in a terrarium, as it will quickly outgrow the tank. After all, your terrarium won’t be self-sustaining if you have to constantly prune plants. Make sure to add some moss to your terrarium to help maintain moisture for the other plants.

4. Pick The Perfect Location

Light is just as important for a self-sustaining terrarium as water and substrate. While you can use grow lights, it’s hard to beat natural sunlight. Terrariums thrive near north-facing windows, as long as the light isn’t too direct.

Try not to put your terrarium on a windowsill, or else it will likely get too much sunlight. Instead, you may want to put your terrarium on a table in a room with north-facing windows. Otherwise, you can simply position grow lights near your terrarium and run them for 6-12 hours.

5. Create A Water Reservoir

Water is essential for a self-sustaining terrarium, but there must be a spot for it to collect. This will stop water from over-saturating the substrate and damaging the plants. The best way to make a water reservoir is to create a small divot for water to pool at the bottom.

Simply dig out a chunk of substrate and redistribute the substrate somewhere else in the terrarium. The water reservoir will help maintain consistent moisture.

6. Populate It With Bugs

Whether you love bugs or hate them, they work wonders to maintain a self-sustaining terrarium. Isopods like pill bugs and sowbugs can help keep your terrarium clean. Springtails are also quite effective, and they help keep the substrate fertile.

That’s because bugs eat plant material, and their waste helps further fertilize the substrate. Springtails are especially useful if you have had problems with mold in your terrarium. You can keep a self-sustaining terrarium without bugs, but bugs maintain a clean environment.

7. Keep Up With Maintenance

Of course, the goal of having a self-sustaining terrarium is to avoid maintenance as much as possible. That said, you must still do simple things to make it thrive, such as rotating your terrarium as needed. This is essential if you see the plants growing too quickly on one end of the container.

You can also fix this problem if you change the lighting setup to make sure all the plants get equal light. It’s also important to pay attention to your plants and watch for dead plant material. That’s not a problem if you have bugs in your terrarium, as they’ll eat the dead leaves.

Otherwise, you must open the lid and trim the dead parts of the plant. You may also need to add water if you no longer see condensation on the glass. It’s also essential to watch for fungus and mold that could harm the plants in your terrarium.

8. Fertilize Your Terrarium Yearly

Hopefully, you don’t have to do much to take care of your self-sustaining terrarium aside from fertilizing it yearly. This isn’t necessary for everyone, but it’s a great idea if you want to ensure the substrate stays healthy. It’s important to only use ¼ of what you’d typically use for a houseplant, or else the plants will grow too fast.

Wait longer than a year to fertilize your terrarium again if the plants are overgrown. You can’t count on terrariums to thrive for years if you don’t re-fertilize the substrate, but it takes some trial and error. Make sure to only put the fertilizer in the soil, so that none of it gets on the plants themselves.

Summing It Up

Pick a roomy container and fill it with 2 ½” of potting soil, pea, gravel, and peat moss. Next, fill your terrarium with a few low-maintenance plants, such as air plants. Add bugs like springtails and isopods to keep your terrarium clean and cut down on mold and fungus.

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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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