It was discovered in 1966 in the Netherlands and contained plants and animals native to Europe. In general, closed terrariums only live as long as their environment allows. If they aren't refreshed with new soil and plants once an year, then they will die after several months. The average lifespan of a closed terrarium is about one year. Here are some factors that will affect how long your terrarium lasts: climate, water quality, soil type, and care will all play a role in how long it can be expected to live. Also, if you add heat-producing elements such as lava rocks or candles, then you need to make sure that you provide enough sunlight to keep these items cool. In short, the longer your terrarium lives, the more likely it is that it has been well-cared for and given the proper environmental conditions. Closed terrariums are not recommended for everyone. Those who are allergic to plants or have small children at home should probably not use this method of keeping pets.