Louis d’Hotman

Terrariums are small gardens in closed or partially closed clear containers. With the use of compatible plants a miniature landscape will give a new dimension to your gardening imagination, make excellent gift ideas for family and friends and hours of gardening fun for the children.

A clear, plastic or glass bowl or container is the first item on the list. This can be a completely enclosed or partially enclosed unit. In a container that is completely closed, a little micro climate will develop where moisture will recirculate, making your terrarium self-sustaining. With an open bowl a little more care will have to be given to the moisture in your miniature garden. But more on all of this later; let’s get to planting up the terrarium.

There are four basic layers to set up at the base of the terrarium. These four layers should take up only the bottom quarter of the container; with the fourth layer being the thickest as this will be the soil into which the plants will be planted. The first layer consists of rough gravel or pebbles and acts as the drainage layer. Any excess moisture can pool in the gravel to be drawn up when needed. The second layer is activated charcoal or fine porous clay. This is a filter layer and together with the Sphagnum moss of the third layer, keeps moisture near the base of the soil layer and also stops the soil from filtering down into the gravel. The soil for the planting layer must be a fine, loose and well drained mix. A seedling soil or herb mix will have the correct consistency.

Now for the plant varieties and your choice of landscape you wish to design. In a terrarium space is limited and this will determine not only the quantity of plants but also keep in mind how large the plants can eventually become. With an open terrarium you have the choice of using taller growing plants, whereas in a closed unit shorter plants or varieties that can be cut back will work best.

A closed terrarium will develop a cycle of evaporation and condensation, so in other words, quite a moist environment. Use plants that have smooth waxy leaves, ferns and ground covers. In this system the hairy leaves of some plants hold moisture for too long and there can be a chance of fungi developing.

Succulents are an excellent plant variety to use in a terrarium and make for interesting landscape ideas. These will work best in an open container or if you do use a closed terrarium; open the lid every now and again to allow some of the excess moisture to escape.

Quick tips before any planting or materials are added to the terrarium. Wash your hands; wash, rinse and dry the terrarium and rinse off the gravel, charcoal and moss. Make sure of a good quality soil. Bacteria, fungi and algae love a warm and moist environment in which to proliferate.

Moisten the soil and make sure that there is not a pool of deep water in the gravel layer. In a closed terrarium the cycle of evaporation and condensation should keep the plants well supplied with water. If there is too much condensation forming on the sides, open the lid to let out some of the moisture. This also allows fresh air into the system which is a good idea. In an open system you will need to keep an eye on your watering. Light is important, but no direct sunlight. In a closed terrarium the heat build-up will cook your plants. When necessary, remove old leaves, spent flowers and clean away any algae.

With the use of compatible plants to create a tropical landscape or a miniature succulent garden, terrariums will give a new dimension to your gardening imagination; create gift ideas for family and friends and craft hours of fun for you and your children.

For any further information and general gardening questions contact Louis at Garden World or visit us on Beyers Naudé Drive in Muldersdrift.
Louis d’Hotman
General Manager