AGRICULTURAL EXTENSION SERVICE
..Circular 149 April 1956
ST. J. SHEEIAN
Assistant Ornamental Horticulturist
A terrarium is a miniature garden enclosed in glass, either
a round glass globe, aquarium, large-mouth bottle, large-stemmed
glass or another type of clear glass container. Terrariums are
ideal for growing difficult plants under adverse conditions. They
produce artificially a more or less ideal atmosphere in the home
in which we can grow numerous plants that could not stand the
normally dry atmosphere of the average home. In addition.
the lustre and reflection of the glass adds interest to the arrange-
ment not found in open arrangements. The glass enclosure also
protects delicate foliage, brittle stems and leaves that would
be difficult to grow in the open, even if the humidity could be
Not only are terrariums relatively simple to make and set up,
but once they have been established, they are easy to maintain
and will thrive very well for long periods with a minimum of
The type of container you select for the terrarium will be
governed by several factors. First of all, choose one that is
suitable to the room where it will be used. One that is 'not
adapted to a certain situation because of shape or size will lose
its effectiveness. Secondly, select your container for ease of
'.1.i;iii.L. Remember that the smaller the opening in the con-
tainer the more difficult it will be to plant.
Once you have selected your container, whether it be one of
those pictured in this circular or another transparent container,
all you have to do is follow these few steps to have a terrarium.
1. First of all, place at least one inch of gravel about the size
of a pea in the bottom of the container. Terrariums are easy
to overwater and some provision must be made to take care of
excess water. Excess water filters down into the gravel and
remains there to serve as a reservoir, gradually returning to
the soil by capillary movement as the soil on top dries out.
2. After the gravel is in place cover it with from three to
four inches of a good organic soil mixture. A mixture of one
part by volume of peat to one part sandy soil is ideal. To this
mixture add and mix one teaspoon of 6-6-6 fertilizer for every 2
quarts of soil. When you place the soil mixture in the container,
you can level it if it is to be seen from all sides or form it into
slopes, depressions and various shapes if it is to be seen mainly
from one side. Many people prefer the latter, as they say it
looks more natural.
3. Any of the following plants can be grown:
A. Native Plants
Linderria ;l' l,.i' T nlo -11,
B. Cultivated Plants
English ivy smalll
Snake plant smalll
r. I II I
Types of Terrariums.
4. The plants should be planted at the'same depth as they
were growing in the wild or in the garden or pot. If you use
narrow-mouth containers you will have to use a long pair of
tweezers and planting sticks in planting the containers.
,/ )' /-: -= ," .-i -
Requirements for a successful Terrarium.
5. A l1.--, cover is a must for most terrariums. It helps to
keep the humidity up and also prevents the terrarium from
drying out too rapidly. It should not be fastened too securely,
since it has to be removed sometimes for a few hours to venti-
late the terrarium when the sides have an abundance of mois-
ture collected on them.
6. Watt.riml is not a problem, since plants in a terrarium re-
quire only a small amount. They should be watered only when
the surface of the soil becomes dry and then add enough water
to moisten the soil again.
The plants will survive for long periods without fertilizer.
The objective should be to keep the plants healthy but growing
slowly, just short of a starvation diet. If a terrarium is fertilized
frequently the plants will soon outgrow it. The terrarium should
be kept away from direct sunlight, as the plants grown in ter-
rariums are those that are naturally adapted to ;r..v irl- in dark,
damp areas in the woods.
COOPERATIVE EXTENSION WORK IN AGRICULTUIflE AND HOMNE ECONOMICS
(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida,
F'lrida State University and United States Department of Arriculture, Coopcratir.,g
JI. G. Clayton, Director