A terrarium is generally described as a closed glass container with the plants growing inside in their own microclimate. Admittedly you do see some terrariums which have a small opening in the top, but not usually more than this. However Kimberly Charles writing in the Fine Gardening magazine asks “Why limit yourself to a single, static design in a closed, foggy vessel?”. The article expands on this theme with designs for each of the four seasons and instructions on how you can do this yourself.

A well-designed terrarium can transform an indoor space. It becomes an instant focal point that invites us to draw?close, examine small details, and enjoy the artistry of nature.
Early terrariums were built in closed containers. They showcased rare plant specimens, protecting them from Victorian England?s?chilly, polluted air. But today?s designs need not be stuffy echoes of a bygone era.
For a chic, contemporary look, try grouping gorgeous plants in an open glass container. Imagine the possibilities: tall, dramatic plants bursting above the rim; flowers or fronds spilling out the front; or an orchid?s arching stem?rising within a slender cylinder. Almost any vase, jar, bowl, or basin could be called into service to hold an enchanting indoor display. Open-topped terrariums are simple to assemble.
My designs start with a base layer?of stone and moss. Plants are tucked in next, with at least one showstopper and companions that complement it and provide contrast. I add a mix of soil and horticultural charcoal to cradle the plants? roots, then top it with a layer of mixed mosses. Natural treasures or?found objects add a playful finishing touch.
Maintenance is also straightforward. Compared to a closed container, which needs precise watering and ventilation to keep?humidity levels balanced, an open terrarium is quite forgiving. Your plants will likely require only about one shot glass of water per?week, with a bit of misting to keep mosses lush. Take care to avoid overwatering as standing?water invites decay.
To keep the design fresh throughout the year, swap in new plants that are inspired by the changing seasons. Knowing that a?combination will spend only a few months in its glass home, you can experiment with some unexpected plant choices, displaying?them when they look their absolute best. The plants you retire can be recycled into new containers, moved to the garden, or?given away. Switching out your plants is almost as easy as arranging cut flowers, and the designs you?create can be displayed in much the same way. Serving as a centerpiece, enhancing an entryway, or beautifying a bedside table, a terrarium?can be moved or changed whenever you want, providing seasonally inspired garden glamour to your home all year long.
Read more: Fine Gardening