How to Make a Bottle Garden: Moss, Plants and the Tricks for Narrow Necks

There is something irresistible about a garden in a bottle. Living moss sealed behind glass, planted through a hole you can barely fit two fingers into, looks like a ship in a bottle that happens to be alive. People see one and want to know how on earth it got in there.

The answer is patience, the right tools and a little restraint. Some things simply won't go into a bottle garden, however much you want them to, and that includes the perfect piece of wood you found on your last walk. The neck decides what goes in, so it's easier to plan around it than to fight it.

This guide covers how to choose a bottle, the tools that make a narrow neck manageable, which moss and plants actually fit (and survive), and how to look after a garden you can't reach into.

What is a bottle garden?

A bottle garden is a terrarium planted in a bottle: a container with a neck much narrower than its body. Classic choices are glass carboys and demijohns, but old apothecary bottles, large cordial bottles and narrow-necked storage jars all work. The glass traps moisture, so the plants inside live in their own small, humid climate and need watering far less often than a houseplant in a pot.

The difference from a jar terrarium is access: in a bottle, every pebble, scoop of soil and piece of moss goes in through the neck.

Where bottle gardens came from

The idea goes back to a London doctor, Nathaniel Bagshaw Ward. Living in Wellclose Square in the East End, he kept failing to grow ferns in the city's polluted air. In 1829 he noticed a fern sprouting inside a sealed glass jar he had been using to keep a moth chrysalis, and realised the closed glass was protecting it. He tested the idea with bottles, bell jars and glazed cases around his house and published his findings in 1842 as On the Growth of Plants in Closely Glazed Cases (Linnean Society).

His glazed boxes, soon called Wardian cases, changed botany. As Kew explains, they let living plants survive months-long sea voyages; Kew was using them routinely by 1847, and the last one arrived from Fiji in 1962. At home, the same principle became the fern case, then the bottle garden. Planted carboys were a long-running houseplant favourite in the second half of the twentieth century, and one of the most famous, planted in 1960, is still going. We tell that story in how long a closed terrarium can live.

How to choose a bottle for a bottle garden

Almost any clear glass bottle can be planted, but some make life much easier.

• Size of the body. Bigger is easier. The RHS suggests around 30cm wide and tall as an ideal terrarium size, because smaller containers limit what you can grow (RHS). A demijohn or carboy gives you room for a proper landscape.
• Width of the neck. Measure it before you fall in love with the bottle. A neck you can get a finger and thumb through is workable for moss and small plants. Anything narrower restricts you to tiny pieces and very fiddly work.
• Colour of the glass. Clear glass lets in the most light. Tinted green or brown glass looks wonderful but cuts the light your plants receive, so give a tinted bottle a brighter spot and choose shade-tolerant moss and ferns.
• A lid or stopper. A cork or glass stopper lets you seal it. Avoid metal screw caps, which can rust in the humidity.

Wash the bottle in hot water, rinse out all the soap and let it dry fully, or soil will stick to the glass on the way down.

Tools for planting through a narrow neck

You will not get your hand inside, so your tools become your hands. You don't need much, and some of the best are already in your kitchen drawer.

• Long tweezers. The single most useful tool. 30cm terrarium tweezers let you place moss and plants precisely at the bottom of a deep bottle, and later pick out dead leaves.
• A funnel. A rolled sheet of paper or card works perfectly. It delivers gravel and soil straight to the bottom without dirtying the glass on the way.
• A small scoop. A mini soil scoop lets you pour substrate down the funnel in controlled amounts.
• A chopstick. For nudging things into place.
• A tamper. Something flat on a long handle, for firming the soil and pressing moss down.

Chopsticks come up again and again with narrow bottles. "I've made bottle terrariums with wine bottles and those are basically too small for anything but a chopstick," says Morgan at The Moss Fairy. "Which, incidentally, is a great tool for nudging things around and into position in such a narrow, confined jar."

For tamping, Morgan has a kitchen trick: "A wooden spoon can also work, but I'd suggest cutting off the end of the handle so it's a flat end. Then you can tamp with it."

How to make a bottle garden, step by step

The layers are the same as any closed terrarium (our beginner's terrarium guide explains what each one does). The trick in a bottle is getting them in cleanly and in the right order.

1. Plan the planting outside the bottle. Lay your moss and plants out on the table in roughly the arrangement you want. It is much easier to change your mind out here than at the bottom of a demijohn.
2. Add the drainage layer. Pour in a few centimetres of clay pebbles or washed gravel through the funnel. This gives surplus water somewhere to go.
3. Add a thin layer of activated charcoal. Optional, but helpful in a sealed bottle, where it helps keep the system fresh.
4. Add the substrate. Pour terrarium soil down the funnel a scoop at a time, then level and firm it with your tamper. Aim for enough depth for roots, and shape it into a gentle slope or hill if you want a landscape. The DIY Terrarium Starter Kit has all three layers ready to go.
5. Plant anything with roots first. Dig a small hole with the chopstick, lower the plant in with tweezers, then push soil around it and firm it in.
6. Add the moss last. Feed pieces through the neck, then use tweezers to position them and the tamper to press them into firm contact with the soil.
7. Clean the glass. Mist the inside of the glass lightly so the water runs down and rinses off any soil. A cork on a stick will wipe off anything stubborn.
8. Water sparingly. The soil should feel like a wrung-out sponge. A bottle loses very little water, so it's easy to overdo it.

The best moss for a bottle garden

Not all moss copes equally well with being fed through a neck. "Feather definitely," says Morgan. "Cushion will break apart if the neck is too narrow. You can use little snippets of bun, like the ones we sell, as accents in a narrow jar terrarium, but larger buns are challenging."

That matches how the two mosses grow. Feather moss is a loose, flexible mat of branching stems, so it folds up to go through the neck and opens out again once it's inside. Cushion moss grows as dense domes, which crumble if you try to squeeze them through a gap. So use soft live feather moss as your ground cover, then add a few bun moss snippets for rounded texture.

What plants can you grow in a bottle garden?

Choose small, slow-growing plants that like humidity and tolerate lower light. The RHS recommends fittonias, peperomias, pileas, hypoestes, small-leaved ferns and compact plants such as Selaginella kraussiana for closed terrariums. It also advises against flowering plants, because you would have to keep opening the container to remove the dead flowers.

Check the eventual size on the label. Many houseplants sold small are young tropical plants that will press against the glass within a year. Our guide to plants that grow well with moss has more suggestions.

How many plants should you put in a bottle?

Fewer than you think. This is the mistake Morgan sees most often in a first bottle garden: "Overambitious belief in what will actually fit. In smaller containers, less is more. Give the moss the spotlight, and it'll find a way to look great on its own. Don't stuff as many tiny plants as you can think of into it."

A bottle garden with one small fern and a carpet of moss will look better, and last much longer, than one crammed with six plants competing for the same few centimetres. A moss-only bottle is a perfectly good bottle garden.

Should a bottle garden be sealed or open?

Both work, and they behave differently.

• Sealed (corked). Moisture evaporates, condenses on the glass and runs back into the soil. The RHS says closed bottle gardens usually need water only a few times a year. Moss and ferns love this. The risk is too much water: if the glass stays heavily misted all day, remove the cork for a few hours to let it dry back.
• Open. A bottle with a narrow neck still holds a lot of humidity even without a cork, but it does slowly lose water, so check it every week or two. The RHS notes that a carboy with a wide top can be easier to manage without a stopper, because the wider neck lets more water escape.

If you're unsure, start corked and watch the glass. Light condensation that comes and goes means the balance is right.

How to look after a bottle garden

• Light. Bright, indirect light. Keep it out of direct sun, which can overheat a sealed bottle, and away from radiators.
• Water. Only when the condensation stops appearing and the soil looks paler. Mist down the inside of the glass rather than pouring water in.
• Tidying. Pick out yellow leaves and brown bits with long tweezers before they turn mouldy.
• Trimming. If a plant starts to fill the bottle, trim it with long scissors, or lift it out with tweezers and replace it with something smaller.

How do you clean the inside of a bottle garden?

Mist the inside of the glass so the water runs down and rinses off dust and soil. For marks it won't shift, wrap a small piece of kitchen paper around a cork on a stick, or the end of a long skewer, and wipe gently.

What if something goes wrong inside?

Most problems in a bottle come from too much water. White fuzz, a sour smell or moss going dark and slimy all mean it's too wet. Uncork it for a few days, remove anything affected with tweezers, and hold off on watering. If one plant has died, lift it out and fill the space with a little more moss.

Frequently asked questions

How do you make a bottle garden?

Pour a drainage layer and then terrarium soil through a paper funnel, firm it with a long-handled tamper, plant small humidity-loving plants with long tweezers, then press feather moss over the surface. Mist the glass clean, water lightly and cork it, or leave it open if the neck is wide.

What plants can you grow in a bottle?

Small, slow-growing plants that enjoy humidity: fittonias, peperomias, pileas, small ferns, selaginella and, of course, moss. Avoid succulents and cacti in a sealed bottle, because they need dry air, and avoid flowering plants.

How long can a sealed bottle garden last?

With the right balance of light and water, a sealed bottle garden can last for many years, and the most famous ones have lasted decades. Our terrarium lifespan article explains why.

Do bottle gardens need watering?

Rarely. A sealed bottle recycles its own water and may need a little only a few times a year. An open bottle loses water slowly and needs checking every week or two.

Ready to plant one?

Find the bottle first, then gather the tools. Long tweezers, a scoop and a chopstick will get you through almost any neck. Our live moss and terrarium supplies are hand-packed in Bristol, with free UK delivery, and we ship internationally.