The key to making beautiful enclosed gardens, which aren’t just a jumble of green leaves sweating behind glass, is to have space around the objects and plants and a sympathetic sense of scale.
• Keep it simple. Three plants is probably plenty. Or forget the plants and try just moss and stones.
• Stand a planted terrarium in a light position but not in direct sun.
• Wood, moss, stones or other natural objects are important to give context in among the plants. They can mimic a full-sized landscape but in miniature.
• Marten uses real fossils in his landscapes as they bring something genuinely old, beautiful but affordable into a modern house and won’t spoil among damp earth and plants.
• The growing medium, which should be very free-draining at the base, can be layered in textures. Add a little crumbled charcoal to keep the soil sweet.
• Terrarium gardeners soon learn how to adapt tools for working in confined spaces. Long tweezers without too much spring, tiny forks or trowels taped to bamboo canes, chopsticks, a length of hose and a funnel to add composts and grit, all are simple to obtain or make.
• Always keep plants which need special conditions together. Don’t try mixing drought-loving succulents with moisture-loving ferns, for example.
• Once plants have established they need little maintenance. In enclosed spaces the moisture should recycle. Trial and error will establish when plants need any extra water.
• Remove any dead or dying foliage immediately to reduce the chance of fungal diseases. Prevent foliage from touching the glass sides. (By Ken Marten,23 Jan 2013)