How to Make a Terrarium for Beginners (Step-by-Step Guide)

Making a terrarium is one of the most satisfying weekend projects you can do, and it's far simpler than it looks. You need a glass container, a few layers of materials, some small plants, and about an hour of your time. That's it. Whether you want a lush little forest on your desk or a low-maintenance succulent garden for your windowsill, this guide walks you through every step from scratch.

What Is a Terrarium, Exactly?

A terrarium is a small, self-contained garden inside a glass container. It can be open (great for succulents and cacti) or closed (better for tropical plants that love humidity). Think of it as a miniature ecosystem you get to design yourself.

The closed kind can even water itself through condensation: moisture evaporates from the soil, hits the glass, and drips back down. Open terrariums need occasional watering, but they're more forgiving if you tend to overwater things. For beginners, I usually recommend starting with an open terrarium and drought-tolerant plants. Less room for error.

What You'll Need

Before you start, gather everything so you're not hunting for supplies mid-project. Here's the basic list:

A glass container (a fishbowl, mason jar, geometric glass vase, or an old candy jar all work well), pebbles or gravel for the drainage layer at the bottom, activated charcoal to keep the water fresh and prevent mold, potting mix (cactus/succulent mix for open terrariums, regular potting soil for closed ones), small plants (more on those below), decorative elements like moss, rocks, small figurines, or driftwood (totally optional but fun), a spray bottle for watering gently without disturbing the layers, and a spoon or small trowel for placing soil without making a mess.

You likely already have a few of these at home. The rest are cheap and easy to find at any garden center or craft store.

Choosing the Right Plants

Plant selection is where a lot of beginners go wrong. Not because they pick bad plants, but because they mix plants with different water needs. A succulent and a fern do not want to be roommates.

For open terrariums, stick with echeveria or haworthia, cacti, air plants (tillandsia), or sedum.

For closed terrariums, try fittonia (nerve plant, which has great patterned leaves), peperomia, baby ferns, sheet or cushion moss, or miniature ficus.

Go with three to five small plants max. Overcrowding looks good at first but causes problems fast once the plants start growing. Give them room to breathe.

Step-by-Step: How to Make Your Terrarium

Step 1: Add the Drainage Layer

Pour about one to two inches of pebbles or gravel into the bottom of your container. This layer keeps water from sitting directly against the roots, which would cause rot. For a taller container, you can go up to three inches.

Step 2: Add Activated Charcoal

Sprinkle a thin layer of activated charcoal (about half an inch) on top of the gravel. You can find this at pet stores in the aquarium section or at most garden centers. It filters bacteria and keeps things from getting funky inside the glass. Don't skip this step. It makes a real difference over time.

Step 3: Add Your Potting Mix

Add two to three inches of your chosen potting mix on top of the charcoal. Pat it down gently so it's stable but not compacted. If you're working with a narrow-necked container, use a spoon or a rolled-up piece of paper as a funnel to get the soil in without coating the glass walls.

Step 4: Plant Your Plants

Gently remove each plant from its nursery pot and shake off excess soil from the roots. Use your finger or a spoon to make a small hole in the soil, place the plant in, and press the soil firmly around the base. Start with the largest plant first, then fill in around it with the smaller ones.

Leave a little space between plants. They'll thank you for it later.

Step 5: Decorate

This is the fun part. Tuck in a few small rocks, press some sheet moss between plants, add a miniature mushroom figurine or a tiny lantern. The decorating is completely personal. Keep it simple or go wild, either way it's yours.

Step 6: Water Lightly

Use a spray bottle to mist the soil until it's just barely damp. For a closed terrarium, you want slightly more moisture. For an open one, less is more. If water starts pooling in the gravel layer, you've added too much. Just leave the lid off for a day to let it dry out.

Caring for Your Terrarium

Once it's made, terrariums are genuinely low-maintenance. Here's what to keep in mind:

Light: Most terrariums do well in bright, indirect light. Direct sunlight through glass can cook your plants. A spot near a window, but not sitting in direct sun, is usually perfect.

Watering: Open terrariums generally need watering every one to two weeks. Stick your finger about an inch into the soil; if it's dry, give it a light misting. Closed terrariums may only need watering once a month or even less.

Pruning: Trim back any plants that are outgrowing their space. This keeps the arrangement looking tidy and stops one plant from crowding out the others.

Troubleshooting: If you see condensation constantly dripping inside a closed terrarium, crack the lid for a few hours. If a plant starts to look yellow or mushy, it's probably getting too much water.

A Few Things That Make a Big Difference

Use clean tools and wash your container before you start. Leftover soap residue or bacteria can cause problems for the plants. Buy plants that are already small (they're often sold as "fairy garden" or "mini" plants). And don't stress about perfection on your first try. Terrariums are meant to be playful.

The whole process takes less than an hour, costs under $30 if you're starting from scratch, and gives you something genuinely nice to look at every day. Once you make one, you'll want to make five more. Fair warning.