How to Make a Terrarium in a Jar: A Comprehensive Guide

Terrariums are miniature ecosystems enclosed in glass containers, creating a unique blend of art, science, and nature. They are not only beautiful to look at, but they also allow you to connect with nature in a very intimate way. This comprehensive guide will take you through the process of creating your own terrarium in a jar, step by step.

What is a Terrarium?

A terrarium garden scene in a clear bottle

Before we delve into the creation process, it’s important to understand what a terrarium is. A terrarium is essentially a miniature indoor garden contained within a clear glass or plastic container. It is a self-sustaining ecosystem that needs minimal maintenance once set up correctly.

There are two types of terrariums: closed and open. Closed terrariums are best for tropical plants that enjoy humid conditions, while open terrariums are more suitable for plants that need less humidity and more air circulation, like succulents and cacti. The focus of this guide will be on closed terrariums, as they are typically the type made in jars.

Materials You’ll Need

To make a terrarium in a jar, you will need the following items:

  • A clear glass jar with a lid
  • Small stones or pebbles
  • Activated charcoal (found at pet stores in the fish section)
  • Potting soil
  • Small plants (ferns, mosses, and air plants work well)
  • Decorative elements (optional, e.g., small figurines, shells, or crystals)
  • A spoon or small shovel
  • Gloves
  • Spray bottle with water

Step-by-Step Guide to Making a Terrarium in a Jar

1. Choose and Clean Your Jar

The first step is to choose a jar for your terrarium. The jar can be any size or shape but should be clear glass to allow sunlight to reach the plants. The jar should also have a lid or cork to create the closed environment needed for a self-sustaining ecosystem. Once you’ve chosen your jar, clean it thoroughly to remove any dust or residue that could affect your plants’ health.

2. Add the Drainage Layer

The next step is to create a drainage layer at the bottom of your jar. This layer will prevent water from sitting in the soil, which could lead to root rot. Add a one to two-inch layer of small stones or pebbles at the bottom of the jar.

3. Add the Charcoal Layer

The activated charcoal layer is crucial in a closed terrarium. It helps filter the air and water, preventing odors and fungal growth. Add a layer of activated charcoal on top of the stones.

4. Add the Soil Layer

Now it’s time to add your soil. The type of soil you need will depend on the plants you’ve chosen. Most small houseplants do well with standard potting soil. Create a layer of soil deep enough for your plants’ roots to grow. This is typically about two to three inches.

5. Plant Your Plants

Now comes the fun part – planting your plants! Make small holes in the soil with your fingers or a spoon. Remove your plants from their containers, gently tease apart their roots, and place them in the holes. Pat the soil around the plants to secure them.

Choose plants that thrive in similar conditions. For a closed terrarium, humidity-loving plants like ferns, mosses, or air plants are good choices. Try to arrange the plants in a way that’s visually appealing but also gives each plant enough space to grow.

6. Decorate (Optional)

If you want, you can add some decorative elements to your terrarium. This could include small figurines, shells, crystals, or even a layer of decorative pebbles on top of the soil. Be creative and personalize your terrarium to reflect your style. Just remember that any decorations should be clean to prevent introducing contaminants to your terrarium.

7. Water Your Terrarium

After planting, give your terrarium a little water. The amount of water will depend on the plants you’ve chosen, but a good rule of thumb is to make the soil moist, but not drenched. A spray bottle is a good tool for watering as it won’t disturb the plants or soil too much.

8. Close the Jar

Once you’ve watered your terrarium, close the jar with its lid or cork. This creates the enclosed environment needed for your terrarium to become a self-sustaining ecosystem.

Maintenance and Care of Your Terrarium

A well-made terrarium requires very little maintenance. Here are some tips on how to take care of your terrarium:

  • Light: Place your terrarium in a location where it will get indirect light. Too much direct sunlight can cause the terrarium to overheat and kill the plants.
  • Water: The closed nature of the terrarium should create a water cycle within the jar. You’ll see water condensing on the walls of the jar and dripping back down into the soil. If the walls of the jar are constantly wet and you can’t see your plants clearly, you may have added too much water. Open the lid to let some evaporate.
  • Pruning: Over time, your plants will grow. If they start touching the walls of the terrarium, you should trim them back. This helps prevent rot and maintain the aesthetic appeal of your terrarium.
  • Refreshing the Soil: Once a year or so, you may want to refresh the soil in your terrarium. This involves carefully removing the plants, replacing the old soil with new soil, and replanting the plants.

Troubleshooting Your Terrarium

Even with careful planning and maintenance, you may encounter some issues with your terrarium. Here are some common problems and their solutions:

  • Mold or Fungus: If you notice white, fluffy patches in your terrarium, it’s likely mold or fungus. This is often due to overwatering or lack of ventilation. To fix this issue, remove the affected plant or soil and replace it. If the issue persists, you may need to transfer your plants to a new container with fresh soil.
  • Yellow or Brown Leaves: If the leaves on your plants start turning yellow or brown, it could be a sign of too much sunlight or overwatering. Move your terrarium to a location with less direct sunlight, and ensure you’re not overwatering.
  • Lack of Growth: If your plants aren’t growing, they may not be getting enough light, or the soil may lack nutrients. Try moving your terrarium to a brighter location. If that doesn’t help, you may need to replace the soil.

Expanding Your Terrarium Collection

Once you’ve gotten the hang of creating and maintaining a terrarium, you may want to try creating different types of terrariums. Each type of terrarium provides a different environment, and thus, can house different types of plants:

  • Desert Terrarium: This is an open terrarium that is great for cacti and succulents. These terrariums require a sandy soil mix and infrequent watering.
  • Aquatic Terrarium: Also known as an aquarium, you can create a mini underwater garden with aquatic plants and even small fish or shrimp.
  • Carnivorous Plant Terrarium: Carnivorous plants like Venus flytraps and pitcher plants thrive in terrariums. These plants require a particular soil mix and lots of humidity.

Creating a terrarium in a jar is just the beginning. There are countless possibilities for the types of terrariums you can create, each one offering a unique way to connect with nature and create something beautiful.

Building a terrarium in a jar is more than just a DIY project; it’s a journey into understanding the delicate balance of nature and our role in preserving it. Terrariums are living, breathing ecosystems that not only beautify our spaces but also serve as constant reminders of the world beyond our walls.

Whether you’re a seasoned gardener or a curious beginner, terrariums offer an accessible and enjoyable foray into the world of plants. And the best part? You’re limited only by the boundaries of your imagination. So, pick up that jar, gather your materials, and let’s bring a bit of nature indoors!