HO-13
1978
630.76
In2mHO
YARD AND GARDEN
HORTICULTURE DEPARTMENT • COOPERATIVE EXTENSION SERVICE • PURDUE UNIVERSITY • WEST LAFAYETTE, INDIANA 47907
TERRARIUMS
John A. Wott, Extension home environment horticulturist
A delightful way to grow a collection of small plants is in a terrarium. A terrarium is a glass garden- an enclosed glass container in which moisture-loving plants are grown. With proper care, a terrarium will create a humid atmosphere that protects tender, tropical plants that are difficult to grow in the normally dry atmosphere of our homes. A terrarium also helps to grow plants, or start new plants, under perfectly controlled conditions.
Years ago, an English botanist devised a Wardian case, a glass box used to grow house plants collected in distant countries. Within the glass enclosure he could grow the plants in conditions almost like those of their natural environment. Because the plants inside a glass enclosure are decorative, the idea was soon used in home interior decorating.

Soil and drainage
A soil mixture of one part sand, one part peat moss, and one part loam should be used in terrariums. One level teaspoon of 5-10-5 fertilizer should be added to a six-inch potful of the soil mixture. Ordinary garden soils used alone are usually too heavy.
Containers

Almost any type of glass container can be used as a terrarium-glass jars, old-fashioned candy jars, fish bowls or tanks, goblets or bottles. The container should be of clear glass and should have a cover. Cloudy glass filters out too much light. A cover is necessary to control the moisture and humidity inside the terrarium. The size of the container is optional, but it must allow leeway for arranging materials. The opening should be large enough to put small plants through with ease.
The size of the container will determine the size of plants and accessories you may use. Small evergreens and deciduous tree seedlings can be used in large containers such as aquariums and dish gardens. Always keep the scale of the plant to the size of the container.
Since terrariums have no drainage hole, provision must be made for drainage. A layer of moss can be used on the bottom of the terrarium as a drainage layer in small containers. For larger containers, broken pieces of pot or charcoal, or a layer of sand or fine gravel may be added after the initial moss layer.

Plants
Many varieties of plants may be grown in a terrarium. These may include either native or tropical plants. It is not a good idea to combine both types of plants in the same terrarium. However, native mosses and lichens can be used even in tropical terrariums. Usually, native plants can be secured along streams and in woodlands. Succulent plants such as cactus and Euphorbia should not be used in terrariums since the humid growing conditions cause them to rot.