DIY: Make Your Own Green Terrarium

If you long over glossy magazine photos of perfect landscapes and gardens but just don’t have the space to grow your own, we’ve got just the project to spur that aspiring green thumb to action – terrariums!

Making your own terrarium is fun, and they’re surprisingly easy to care for. They’re the perfect starter project for anyone who wants to plant a first garden, and they’re also a great way for plant lovers to bring their outdoor skills inside to add to their home decor. These mini, tabletop gardens add a beautiful and eye-catching addition to any surface, including desks and dining room tables.

A terrarium is like a house plant, but the focus isn’t just on the leaves. Instead, plants are added to a glass jar that shows off the whole miniature ecosystem you’ve created, including the soil and the roots. Many terrariums use more than one plant to add interest, and terrariums can also be made from unique containers like coffee urns, cookie jars and oddly-shaped laboratory beakers — the only limit is your imagination.

In addition to their beauty, terrariums also help reduce air pollution in your home by exchanging carbon dioxide for oxygen and filtering out harmful volatile organic compounds (VOCs). Think of your new terrarium as a tabletop air filter that requires no electricity to operate and is far lovelier than any machine.

Ready to get started? Gather these materials, and you’ll be creating your very own eco-universe in no time!

What’s Needed

  • A glass container
  • Glass beads, small pebbles or aquarium gravel
  • Activated charcoal
  • Potting soil
  • One or more suitable plants
  • Decorative accessories, like ceramic figurines

A Note About Choosing Plants

Even the brightest indoor spaces aren’t as sunny as the outdoors, so it’s important to choose plants that will thrive in low light. A terrarium also limits the size of the plants you can grow, so it’s also a good idea to choose compact varieties instead of plants that will outgrow your container. Finally, the best terrarium plants are ones that appreciate high humidity, since your glass container won’t have a drainage hole in the bottom and will hold in lots of moisture. These plants fit the bill:

  • Aquamarine
  • Golden clubmoss
  • Nerve plant
  • Starfish plant
  • Strawberry begonia
  • Variegata
  • Variegated spider fern (though other fern varieties will also do well)

Step One: Create Drainage

Your plants will need water, but their roots will rot if they’re constantly submerged in standing water. Add at least an inch of gravel or pebbles first for drainage. Feel free to choose decorative pebbles in interesting colors — part of the charm of a terrarium is seeing all of its layers!

Step Two: Prevent Disease

Add a half-inch layer of activated charcoal over your pebbles. Activated charcoal is a highly absorptive material that will prevent bacteria and mold from growing and reduce toxins that can build up in the closed environment of a terrarium. It will also prevent any odors from developing. While activated charcoal is a must in closed or semi-closed terrariums, you could replace it with sand in a terrarium with a very wide mouth that offers lots of air flow.

Step Three: Add Soil

Be sure to choose potting soil that’s recommended for the type of plant you’re planning to grow. Succulents have different needs than flowers, for example, so look for soil designed for house plants and the particular varieties you’ve chosen. Add enough soil to cover your plant’s height in its original container, then add an extra two to three inches to provide room to grow.

Step Four: Plant Your Greenery

Remove your plant from its original pot and gently break apart the root ball with your fingertips. If the roots are very long, you can trim them to better fit into your terrarium. Use your hands to make a space for your plant in the soil and press the root ball into place, pressing firmly and making sure the plant is at the same depth it was in its original pot. Add or remove potting soil as needed to get the depth right.

Step Five: Decorate

Once you’re happy with the positioning of your plants, add your decorative items. A layer of moss over the soil adds texture and another shade of green for a completely natural look, while whimsical ceramic figurines, sea shells or other waterproof items will make the terrarium an original work of art. Get creative on this step to find a look that matches your tastes and existing decor.

Step Six: Water

Your terrarium will need an initial shot of water to get established. Add just one spoonful of water at a time until the soil looks evenly moistened all around the container. It’s important to go slowly during this step, because your planting container doesn’t have a drainage hole — the water that ends up in there will stay there, and you don’t want the roots to become too wet.

Ongoing Care For Your Terrarium

Keep your terrarium in a bright space, but avoid direct sunlight so that the delicate plant leaves don’t turn brown. Open terrariums will need to be watered about once a week, but ones that are closed or nearly closed function as independent ecosystems. In the case of a closed terrarium, the water you just added will condense on the side of the container and act like tiny rain clouds that keep the soil moist without the need for additional watering. It’s a good idea to open a closed terrarium occasionally to air it out; if you lose all condensation when doing so, add a couple teaspoons of water to replenish before closing again.

Once you’ve designed one terrarium — and experienced just how easy it is to enjoy some fresh greenery in your home — don’t be surprised if it becomes a bit of an obsession. If you find yourself looking at every glass container as a potential terrarium, go ahead and indulge! Terrariums look great in every room of your house, and they also make thoughtful gifts for friends and family. Just add a brief note about how to care for them, and you might just convert your loved ones to the wonders of terrariums, too.