The Mysterious Growing Fern and the History of Terrariums

terrariumIn 1829 Dr. Nathanial Ward became highly aware of the harmful effects the factories of London were having on the quality of air surrounding his home. While performing an experiment he inadvertently made a discovery which would lead to the establishment of terrariums and provide proof of the need for pollution control.

Making a Terrarium

Having a desire to study metamorphosis, Dr. Ward placed the cocoon of a sphinx moth in some moist soil within a sealed glass jar. During the next few days he observed the process of the water cycle occurring within his container. He noticed throughout the day the sun would heat the air inside the glass causing the water to evaporate. The water later condensed forming tiny droplets on the lid which would then return to the soil to repeat the cycle. The jar provided a moisture balanced environment for his cocoon and to his surprise something just as wonderful and mysterious.

Before his sphinx moth emerged, Dr. Ward noticed a fern beginning to grow in his moist soil. He shared his amazement and thoughts about the seedling fern within in his book On the Growth of Plants in Closely Glazed Cases written in 1852 (second edition). He said, “I could not be struck with the circumstance of one of the very tribe of plants which I had for years fruitlessly attempted to cultivate, coming up.”

Concerns of Air Pollution

Upon contemplating how and why the plant was growing within his jar he concluded the container consisted of all the needed requirements for plants to grow. They had sunlight, nutrients from the soil, moisture, air flow, and proper temperature. He also reasoned this particular fern was growing because of the difference of air quality.

Dr. Ward realized the only difference between the ferns he had failed to grow in his back yard for the last several years and the fern which was healthily growing in his enclosed case was the quality of the air. Because he had sealed the jar, the dangerous gases and other pollution surrounding his home were not affecting the plants inside.

Wardian Cases

He continued to research and study pollution and sealed glass cases for many years. His initial experiment developed into new methods of shipping and exchanging plants across many different countries. As the popularity of his cases grew they became known as Wardian Cases and an exciting hobby for plant enthusiasts. People started to display exotic plant collections in decorative cases inside their homes.

Terrariums made today are a direct result from Dr. Ward’s experimentations and studies.

Teaching Children about Pollution

Creating a terrarium reveals the process which occurs not only within these sealed glass cases but also within the earth’s atmosphere. Terrariums provide an excellent teaching tool. They allow children to witness how plants grow and by teaching the history behind these magnificent cases they realize how delicate life can be.

The quality of the air we breathe has been a concern for many years. Making a terrarium is a wonderful project for which children and adults can contemplate the value of clean air. They can consider ways on how they can help keep the earth healthy by recognizing the need for pollution control.


Sources: Google Books On the Growth of Plants in Closely Glazed Cases

Kayatta, Ken and Schmidt, Steven, Successful Terrariums, Houghton Mifflin Company, 1975


Best of luck in all that you seek and Treasure the Adventure!

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1 Response

  1. MartinS says:

    At first I thought this was “The Mysterious Growing Fenn…” 🙂

    Then this made me think of what’s going on in London this summer with the release of “The Big Friendly Giant”:

    “This summer, the streets of London were transformed with magical giant Dream Jars to celebrate Roald Dahl’s 100th birthday and The BFG movie release.”

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