Sealed plant display units (terrariums) are more modest than plant windows, but equally as beautiful when taken care of properly.  They are available in various sizes from small glass cases to larger stands with their own heating and lighting.  These terrariums work on the principle of the “Wardian case”:

When exotic plants became desirable, they would be transported from their exotic lands to Europe.  However, because of climatic changes, only a precious few plants would survive their trip.  These few surviving plants would be extremely hot commodities and priced accordingly.

In the first third of the nineteenth century, Dr. Nathaniel Ward discovered by accident what would be the ideal “packaging” for these plants.  He cared very little about plants and a whole lot more about butterflies, his hobby.  He usually set his caterpillars to pupate on a layer of soil in closed glass containers.  One of these containers lay in a corner, forgotten for months.

When this container came to light once more, Dr. Ward discovered that a small fern was growing in the container.  He discovered that the moisture from the soil had evaporated, condensed on the inside of the glass and then when cooled, trickled down once more into the soil.  As a result, the fern had enough moisture to develop during the time the container had been shoved aside and ignored.

Using this principal, not only were containers for the transport of precious plants made in artful designs, but “Wardian cases” were also made as big as tallboys and placed in the salons of European high society.  They were usually planted with ferns so they were called “ferneries”.

Anyhow, because water circulation, respiration, and photosynthesis take care of themselves in an enclosed space, these units require so little care.  The plants suited to them require very little nutrients.  These terrariums are very easy to care for.