What Is a Desktop Terrarium?

A terrarium is a miniature garden enclosed (or partially enclosed) in a glass container. It's one of the most satisfying DIY projects for anyone who wants to bring greenery to their desk without committing to a collection of individual pots. Done well, a terrarium is low-maintenance, visually striking, and genuinely therapeutic to build.

Choosing Your Container

Almost any clear glass vessel works. The most popular options include:

  • Geometric glass terrariums — angular, modern, and widely available online
  • Wide-mouth glass jars — repurposed apothecary jars or large mason jars work beautifully
  • Fish bowls or brandy glasses — easy to find and naturally elegant
  • Cloche bell jars — perfect for a closed, humid environment

Decide between open (good for succulents and cacti, which prefer dry air) and closed (good for tropical plants like moss and ferns, which love humidity).

What You'll Need

  • A clean glass container
  • Small stones or gravel (for drainage layer)
  • Activated horticultural charcoal (prevents bacterial growth)
  • Potting mix suited to your chosen plants
  • Small plants or cuttings
  • Decorative top dressing (sand, moss, small pebbles, miniature figurines)
  • A long spoon or chopstick for placing and adjusting elements

Step-by-Step Instructions

  1. Clean your container — wash with warm water and allow to dry fully. Any residue can introduce bacteria.
  2. Add a drainage layer — pour 2–4 cm of small stones or gravel into the base. This prevents plant roots from sitting in standing water.
  3. Add a charcoal layer — a thin layer (about 1 cm) of activated charcoal on top of the gravel keeps the environment fresh and odour-free.
  4. Add potting mix — add enough soil for your plants' root systems, usually 5–8 cm. Use cactus mix for succulents; peat-based mix for tropical plants.
  5. Plant your greenery — use a chopstick or long spoon to make small holes and guide plants into position. Work from the back of the container to the front. Leave breathing room between plants.
  6. Decorate the surface — cover exposed soil with moss, sand, or small pebbles. Add miniature ornaments or stones for personality.
  7. Water gently — use a spray bottle rather than pouring water directly. For closed terrariums, a light misting every few weeks may be all that's needed.

Best Plants for a Closed Terrarium

  • Sheet moss or cushion moss
  • Nerve plant (Fittonia)
  • Baby tears (Soleirolia soleirolii)
  • Miniature ferns

Best Plants for an Open Terrarium

  • Echeveria and other rosette succulents
  • Haworthia
  • Air plants (Tillandsia)
  • Miniature cacti

Ongoing Care

Once established, terrariums are remarkably self-sufficient. A closed terrarium can go weeks without water as it recycles its own moisture. Open terrariums need light watering every 1–2 weeks. Both benefit from indirect light and should be kept away from direct sun, which can overheat the glass and scorch plants.

Trim any plants that grow too large, and remove dead leaves promptly to prevent mould. With these simple habits, your desktop terrarium can thrive for years.