🌿 Some links in this post are affiliate links. If you shop through them, we earn a small commission at no extra cost to you. It's one of the best ways to support Humble Acres. Thank you!

Building a terrarium is one of the most rewarding things a plant lover can do. You get a living, breathing miniature landscape in a glass container — and once it’s set up correctly, it practically takes care of itself. The key is choosing the right terrarium plants: ones that fit the environment, stay small, and thrive together.

→ Shop complete terrarium kits on Amazon →

This guide covers the best plants for both closed and open terrariums, what to look for when building your first one, and the gear worth buying.

Closed vs. Open Terrariums: Which Plants Go Where?

Before picking plants, you need to decide what type of terrarium you’re building. This determines everything.

Closed terrariums trap humidity and recycle moisture, creating a tropical microclimate. They work best with moisture-loving plants like ferns, mosses, and fittonias. Open terrariums have no lid — humidity escapes, making them ideal for succulents, air plants, and cacti.

Mixing the two types is the most common mistake beginners make. A succulent in a closed terrarium will rot. A fern in an open terrarium will dry out and die.

Best Plants for Closed Terrariums

These plants love humidity and low-to-medium indirect light — perfect for a sealed glass container.

1. Fittonia (Nerve Plant)

Fittonias are the showstoppers of closed terrariums. Their leaves are veined in white, pink, or red, and they stay compact — usually under 6 inches. They love the consistent humidity of a sealed container and will tell you when they need water by dramatically wilting (then bouncing back quickly once watered).

2. Cushion Moss

Moss is the best ground cover for closed terrariums. It fills gaps between plants, holds moisture, and gives the whole display a lush, forest-floor look. Sheet moss and cushion moss are the most popular choices and widely available online.

→ Shop preserved cushion moss on Amazon →

3. Miniature Ferns

Look for compact varieties like button fern (Pellaea rotundifolia) or lemon button fern. Full-size ferns will quickly outgrow a terrarium, so size matters here. Miniature ferns add height and movement to a terrarium without taking over.

4. Pothos (Small Cuttings)

A single pothos cutting placed at the back of a closed terrarium will slowly trail and fill the space beautifully. Use a small cutting and trim it back once or twice a year to keep it in check. Golden pothos and marble queen both work well.

Best Plants for Open Terrariums

Open terrariums need plants that tolerate drier conditions and bright indirect light.

1. Echeveria Succulents

Echeverias are the classic open terrarium plant — rosette-shaped, colorful, and slow-growing. They come in dozens of varieties, from pale blue-green to deep burgundy. Plant them in well-draining cactus mix and give them bright indirect light.

→ Shop cactus & succulent potting mix on Amazon →

2. Air Plants (Tillandsia)

Air plants need no soil at all, which makes them perfect for open terrariums with sand, pebbles, or driftwood. Mist them once or twice a week and make sure they get airflow — a closed terrarium would trap too much moisture around their leaves. See our complete air plant care guide for specifics.

3. Haworthia

Haworthias are a terrarium favorite because they’re small, slow-growing, and tolerant of lower light than most succulents. They look similar to aloe but stay compact. Great for geometric terrariums on shelves away from windows.

→ Shop geometric glass terrariums on Amazon →

What You Actually Need to Build a Terrarium

The plants are just one part of the equation. Here’s what else goes into a well-built terrarium:

  • Glass container — geometric terrariums, fish bowls, or hinged-lid apothecary jars all work. Size matters: bigger is more forgiving.
  • Drainage layer — pebbles or LECA at the bottom to prevent root rot in containers without drainage holes.
  • Activated charcoal — a thin layer above the pebbles filters the water and prevents bacterial buildup.
  • Appropriate soil — tropical potting mix for closed terrariums, cactus/succulent mix for open ones.
  • Decorative top layer — sand, moss, small stones, or bark to finish the look.

→ Shop activated charcoal for terrariums on Amazon →

→ Shop LECA clay balls for drainage on Amazon →

Ready-Made Terrarium Kits Worth Buying

If you’d rather skip the sourcing and get everything in one box, terrarium kits are a great option — especially as gifts. Look for kits that include the container, substrate layers, plants, and instructions. The best ones on Amazon include everything down to the tweezers.

When shopping, prioritize kits that specify whether they’re for tropical or succulent plants — a kit with the wrong substrate for your chosen plants will cause problems fast.

Common Terrarium Mistakes to Avoid

  • Overwatering closed terrariums. A properly sealed terrarium barely needs watering — condensation on the glass walls is a sign it’s cycling correctly. If you don’t see any condensation, add a small amount of water. If the glass is completely fogged, crack the lid for a few hours.
  • Using regular potting soil for open terrariums. Standard potting mix retains too much moisture for succulents and cacti. Always use a well-draining cactus mix or add perlite.
  • Putting plants together that have different needs. Grouping a moisture-lover with a drought-tolerant plant in the same container means one will always suffer.
  • Choosing plants that grow too fast. Fast growers like pothos or tradescantia will quickly take over. Stick to slow-growers for low-maintenance displays.

The Bottom Line

Terrarium plants succeed or fail based on two things: matching the plant to the container type, and starting with quality plants. Get those two things right and you’ll have a living display that thrives for years with minimal effort.

For more on plants that work well in compact, glass-enclosed environments, explore our guides on succulents, air plants, and low light houseplants.