Terrarium How-To

Terrarium How-To 

Gardeners have been enjoying the practice of planting terrariums for a couple hundred years now. They were historically referred to as Wardian cases, named after their creator, botanist Nathaniel Ward. They became quite fashionable during the Victorian Era and have once again become very popular.

When selecting your plants, you’ll want to ensure they all require similar cultural conditions. For example, don’t pair ferns, which require moist conditions and relatively lower light levels, with succulents, which require drier conditions and higher levels of light.

Whether you select an opened-top terrarium vs a closed-top terrarium will also dictate the plants you select. Closed-top terrariums are far more humid than opened-top terrariums. Succulents, for example, require drier conditions and should therefore never be planted in a closed-top terrarium. Ferns, on the other hand, love humid conditions and are at home in a closed-top terrarium.

Materials required:

  • Terrarium
  • Potting soil
  • Gravel
  • Activated charcoal (available at pet or aquarium shops)
  • Plant material


  • Layer about an inch of gravel on the bottom of your terrarium. Terrariums don’t have drainage holes like most pots, so a layer of gravel will allow excess moisture to gather in the bottom of the terrarium and help increase drainage.
  • Add a layer of activated charcoal, just enough to cover the gravel. The charcoal will act as a filter and absorb any excess organic compounds, keeping the terrarium healthy and fresh. This is particularly important in closed-top terrariums which are much more humid than opened-top terrariums.

  • Add a layer of pre-moistened potting soil above the charcoal. The depth should be enough to accommodate the plants’ roots. Selecting a potting soil with a slow release fertilizer built in is helpful, as fertilization will be one less thing you’ll have to consider for the first few months.
  • Arrange your plants in a pleasing fashion and plant them into the soil.

  • If you pre-moistened your soil, your terrarium won’t require any additional watering at this point. You’ll want to periodically check your terrarium and water only when it is required. Closed-top terrariums will require infrequent watering, as opposed to opened-top terrariums which will require water more frequently. Be careful not to over-water your terrarium. Consider the cultural conditions of the plants you have selected and water accordingly.
  • Place your terrarium in a bright location, but out of direct sunlight. An east or west facing window is ideal. South facing can be a bit too strong, particularly for closed-top terrariums which can build up quite a bit of heat.
  • As plants grow, your terrarium will require regular maintenance in the form of pruning, just to keep things looking tidy.

Watch the how-to on CTV's Your Morning: