Horticulture Principles and Practices

FIGURE 25–5 Assortment of
tools used in creating a terrarium.
These tools are largely homemade
and include cutting, cleaning,
scooping, picking, grabbing,
and compacting tools.
Growing medium
Charcoal
Gravel
FIGURE 25–6 Typical layering
of a terrarium. Drainage
material lines the bottom, followed
by a sprinkle of charcoal
for deodorizing, and topped with
the growing medium.
and development. To provide good drainage, the bottom of the container should first be
lined with a layer of coarse material such as washed gravel, sand, or pieces of broken pottery
(Figure 25–6). To prevent this reservoir for excess water from being destroyed, a
layer of sphagnum moss may be spread over the drainage layer as a retaining layer before
adding the growing medium. In a closed system, odors tend to build up over time because
of the decomposition of organic matter by bacteria. To deodorize the closed environment,
a small amount of activated charcoal may be sprinkled over the sphagnum moss. Alternately,
lumps of charcoal may be used in place of gravel to line the bottom of the container
to about 1 to 2 inches (2.54 to 5.1 centimeters) deep. The planting medium may be
purchased from a nursery store or made at home. Fertility management is important in a
terrarium, since in a closed environment certain nitrogenous fertilizers tend to release
ammonia gases over time; these gases can be toxic to plants and kill them. Using chemical
fertilizers in a terrarium, especially a sealed one, is therefore not recommended.
25.5 PLANTING
The tools described earlier may be used for planting: the spoon to dig a hole, the forked
stick or pair of sticks for lowering the plant into the planting hole, and the dowel for firming
the soil around the plant. The hole should be large enough to hold the root mass.
After removing the plant from the original container, some of the potting medium should
be removed before transplanting. Plants to be located near the side of the bottle should
be planted first. For a bottle garden intended for all-around viewing, the tallest specimens
should be located in the center and the shortest near the container walls. If the unit
is intended to be displayed against a wall, a slope design may be a better choice. In this
design, the soil is banked up against the wall rather than leveled off. Plants with a lot of
foliage may have to be gently bent to maneuver them through the narrow neck of a bottle.
Plants should be arranged such that no plant is obscured by another. The arrangement
25.5 Planting 707