A few years back, I started making terrariums. I saw them everywhere and they reminded how I loved the ones my mom used to make when I was young. I was fascinated with the little tiny world that was self sufficient. Several years since my first one, I realize how easy and versatile they are. Some of my first experiments have never been watered since the day I put them together! With the tops on, the moisture heats up and condenses during the day, and then replenishes the soil at night. They also can survive on very little light...especially if you use mosses and things found in the woods. I have a few that are never near light.
I collect mosses and lichen in the woods on walks, along with dead branches and rocks that add color and form. Little did I know the organisms they carried! Months later, as the moss started growing in ways it doesn't in the wild, small tiny flying insects hatched, lived, apparently reproduced, and then went back to the soil. They continued this cycle for several years.
So this is how I make these little beauties....I get a covered, or sometimes open glass container. Often Home Goods or other home store will have these for a inexpensive price. (Open containers will need to be watered!) Then put gravel in the bottom, 1 inch or so. This can be simply from your driveway or woods, or beautiful river rocks purchased at a garden center. Then a short layer of charcoal. This I get from our burn pit, but could be from the fireplace or wood stove. Rinse off before you put on top. Then comes the soil. I use top soil, or compost..something that isn't potting soil, since that usually has perlite and looks artificial. Plant material comes next, and remember less is more.
Try different things, look for color and texture variety. Garden Center (even Home Depot) small plugs, the woods, small shade seedlings from garden perennials...all good choices. Then the fun part...mosses, lichen, gnarly branches, shells, rocks can be added. I add great bug specimens (that die of natural causes) suspended on wire. A great dried dragonfly or bumble bee hovering on wire adds drama but won't last long (because of the moisture.)
Ok, now your turn! Add some green to a dark corner without a window, and never water again!