Use a bamboo skewer or a chopstick to gently brush dead leaves out from under the terrarium plants. The skewer can also be used to dislodge dead leaves that are still attached to the plant.
Grasp dead leaves using tweezers, tongs or chopsticks. Lift them from the soil and remove them from the terrarium.
Attach the razor blade or penknife to a bamboo skewer or chopstick with small strips of duct tape. Insert the cutting tool into the terrarium carefully and cut any leaves that are too large to fit through the terrarium opening. Use the tweezers or tongs to grasp and remove the cut up leaves from the terrarium.
Examine the dead leaves that have been removed. While dead and brown they will likely be limp from the humidity in the terrarium. There may also be black spots, which are a result of the leaves beginning to decay. These are normal and not a concern for the health of the terrarium. Fuzzy growth of any color on dead leaves is a sign of fungus growing in the terrarium that may need to be treated.
Prune plants with the razor blade or penknife. Cut back sections of the plants that have become overgrown or leggy. Any plant parts that look unhealthy or pale should also be pruned. Remove the pruned plant parts from the terrarium using the tweezers or tongs.
Use a bamboo skewer or chopstick to check the water level in the terrarium. Soil should be moist but not soggy or wet. If the soil is too wet, leave the cover off the terrarium for several days to allow water to evaporate. Soil that is dry should be watered by misting the terrarium with a spray bottle.