Terrarium. Literally, the word means “little earth”; it amounts to controlling the humidity within a small glass container while growing plants is a miniature world under glass. The container can be any shape or size desired. Glass should be clear for maximum light infiltration, and the container may or may not be covered, depending on the size of the opening. If a cover is used, make it clear glass or kitchen, wrap.
The principles of an attractive design or setting apply for the terrarium just as they, do for any landscape design. Large containers with larger openings are easier to work with in arranging the plant materials. Containers such as water carboys with narrow necks and openings pose more of a challenge in arranging the plant materials. Here one would need to fashion his own particular tools for the job such as wire coat hangers, long -handled spoons and doweling, Plant media and drainage are important. Smith suggests a base of charcoal no more than one – half inch in depth. Next, place a thin layer or sheet of moss on top of the drainage material with the green side facing outward against the glass. A soil mix consisting of one part sand, one part sphagnum peat moss and one -half part soil completes the plant media. No fertilizer is added to the mix. Incorporate pebbles, twigs, or a broken piece of mirror (to serve as an artificial pond) as a focal point around which plants are placed.
Carefully make holes in the soil for the plants and arrange them in a pleasing and logical manner. Many times cuttings that are not* rooted can be placed in the terrarium to take root in the moist environment. Place plants so they are not crowded or touching the sides of the container. Once planted, mist the interior of the container with a bulb sprayer and cover. Observe what takes place over the next few days, if the interior fogs too much; remove the cover to permit plantings to dry a day or two. If beads of moisture collect on the interior of the glass, but do not run, then the watering is about right.
The tendency is to over water. Hold back until the soil surface appears dry or plants show slight wilting, then water just enough to moisten the soil. Place terrarium where it receives diffused – not direct – sunlight. Pinching and trimming help shape plants to the environment, and if a few-plants become too vigorous in their growth for the size container, thin them out. Plantings should last one to one and one -half years before replanting or replacing soil.
Some plants that may be used in terrariums are native mosses or lichens from woodlands and along stream banks, maidenhair fern, and asparagus fern, peering hemlock, juniper, pine, yew-seedlings, croton, English ivy, wandering jew, aluminum plants, baby tears and boxwood are better emulsifiers than others.