Water & Irrigation

Water & irrigation in sealed terrariums

A sealed glass garden is a closed, autonomous ecosystem, which means terrarium watering should be minimal and intentional. In a properly balanced sealed terrarium, irrigation is typically needed only a few times per year, not weekly or monthly like traditional houseplants.

Let the system guide you. Moss and soil are the most reliable indicators for terrarium water needs. When the moss appears dry, gently lift it and check the soil beneath. If the soil feels dry to the touch, add one to two teaspoons of non-calcareous water (filtered, or boiled and cooled), adjusting carefully to the size of your terrarium.

This is a practice in precision, not abundance. You are restoring moisture balance, not saturating the soil or flooding the ecosystem.

Excess water & condensation in terrarium care

Seasonal temperature fluctuations can increase condensation in terrariums, especially in sealed environments. A light misting on the glass is normal; persistent or heavy condensation is not. If excessive moisture builds up, remove the lid for 24 hours or gently wipe the glass with a paper towel to release excess water.

Ongoing condensation encourages fungal development in the soil and micro-algae growth on terrarium glass. While these organisms don’t usually harm the plants, they reduce visibility and compromise aesthetics.

Condensation can also be triggered by direct sunlight and elevated temperatures. If this occurs, move the terrarium away from direct sun immediately and allow the internal temperature to normalize before making any watering adjustments.

The TerraTamar principle

In terrarium care, water is not about generosity, it’s about restraint.

A well-balanced terrarium ecosystem thrives on just enough, adjusted slowly over time.

Minimal input preserves clarity.

Precision preserves life.