Genius in a bottle: Grow succulents in terrariums for charming tabletop glass houses

Doctor Nathaniel Ward made a remarkable discovery in 1829. For safe keeping, he laid a hawk-moth pupa on damp soil in a small glass case. 

Weeks later, a baby fern and seedling grass appeared, growing in the same soil.

The case had become a sealed, self-sustaining habitat. Moisture and nutrients recycled naturally, creating a tiny ecosystem. Wardian cases became widely used for transporting vulnerable plants. 

They also caught on as terrariums; small, enclosed habitats for specialised plants.

Modern terrariums come in all shapes and sizes. Some are exclusively for plants. Others can house small animals such as frogs or stick insects all in a natural, self-sustaining habitat.

From the outside, their occupants look healthy and beautiful. Within, a miniature habitat provides ideal conditions for specialist plants.

You could develop a tiny sphagnum moss bog, furnished with wetland plants such as sundews or Venus fly trap.

In contrast, with sand and mini-rocks, you could create a micro-desert, planted with little succulents. To succeed, a terrarium needs suitable temperatures, light and moisture for the plants being grown.

THE RIGHT HABITAT

Terrariums can be almost any size. You could make a micro-garden in a 2lb pickle jar or even a clear-glass bottle.

For children in lockdown, bottle or jar gardens could be fun. They’re also a way of showing kids how to nurture living plants. On a larger scale, cases or glass and metal terrariums make impressive tabletop greenhouses. 

Some have their own stands. What you can grow depends on light levels, temperatures and moisture levels.

Near a sunny window, especially if south-facing, you’d need heat-proof plants. That suggests slow-growing desert dwellers such as cacti and succulents. 

Those can be set in a gritty or sandy micro-landscape. In lower light levels with steady temperatures, think of natural forest floors or shaded banks. Ferns, primitive plants known as clubmosses and even a few flowering varieties could be suitable, provided they stay small.

You can’t get your hands into narrow necked bottles or jars. So you’ll need special long terrarium tools including extended forceps. Wide-neck containers are better for young children.

PLANT CARE

Plant choice depends on plantarium size and habitat. Cacti, succulents and other desert plants need little humus to thrive. Plant those in readymixed cactus potting compost.

You can lay decorative sand, shingle or stone around them. Suitable succulents include pebble-like, flowering lithops, quaint-looking haworthia species or pearly moonstones — Pachyphytum oviferum. 

Modest trailers such as Sedum morganianum would also blend in. Cool, humid-loving plants need not be exotic. 

You’ll find mosses almost anywhere shaded in your garden. Pull up small tufts of those and plant them in a terrarium. They’ll thrive if conditions are right.