Ecosystem in a bottle: The eternal garden

Do it yourself

The eternal garden is easy to build, looks beautiful and best of all: it doesn't need to be watered for years. You can create a fully functioning ecosystem using things you likely already have at home! Check out our DIY guide below.

How does the ecosystem in a bottle work? The photosynthesis of plants converts water and carbon dioxide into atmospheric oxygen and carbohydrates. The resulting oxygen and carbohydrates are converted back into water and carbon dioxide by tiny organisms living in the soil. Just like this cycle, many others (nitrogen cycle, water cycle, etc.) take place in your bottle.

Learn more about your mini ecosystem

How does Photosysthesis work? How large can such an eternal garden get? And what does NASA have to do with it?

Below you can find additional information about your eternal garden and links to information material we found online!


  • Suitable for age group: 6-99 years

  • Especially interesting for: Kids and young adults, gift makers,
    plant lovers and hobby gardeners

  • Preparation time: about 1 hour


  • You need:

  • 1 airtight sealable glass

  • Some gravel or sand

  • A few small pieces of charcoal or lava granules

  • Unfertilized flower or garden soil or coconut soil

  • Small tropical and shade-loving plants

  • Some moss

  • Some tap water

  • Stones, figures etc. to decorate the glass (optional)


Step 1:
Fill gravel or sand into the glass

The lowest layer allows the water to be absorbed toward the bottom. For this purpose, fill gravel or sand into the sealable glass to cover the floor. This prevents waterlogging and your plants' roots won't become too wet.

Step 2:
Put the coal on top of the lowest layer

The charcoal has a disinfecting effect and serves to kill harmful microorganisms and bacteria. For this purpose, place a few pieces of charcoal on the sand or gravel.


You can use lava granules instead of gravel/sand and charcoal if available.

Step 3:
Planting the plants into the soil

Fill unfertilized flower, garden or coconut soil onto the lower layers. Various smaller tropical and shade-loving plants can be planted here. You can now lay moss on the places where the substrate is uncovered, so that the moisture is retained in the soil.

Step 4:
Watering and sealing

Finally, add some tap water.
You can now decorate the glass from the inside (optional).
Then close and seal your glass.

Step 5:
Finding a balance

It can take a few days until your garden is in balance.
Observe it and open or water it as needed.
Once your eternal garden is in balance, there is no need to water it anymore.

The right amount of water in the glass:
There are always a few drops of water on the lid and in the glass.

Too much water in the glass:
If the inside of the jar is steamed up, you can open it for a few hours to allow excess water to evaporate.

Too little water in the glass:
If no drops are visible on the lid or the edge of the glass, open the glass and pour a little water.

Have fun with your
eternal garden!

Learn more!

Your eternal garden is a small ecosystem consisting of soil, plants, microorganisms, air and water. Not a drop of water is lost in this small world - just like in the cycle on Earth.

The ecosystem works in the following way: The sun heats up the air inside and the humidity rises as haze. Tiny water droplets settle on the lid and the glass. Once the sun has set, the air cools down again inside the glass. The water droplets flow together, become heavy and "rain" down.

By the way, the ecosystem in the glass also exists as a miniature sea: the Ecosphere is an aquarium in a sealed glass sphere where the inhabitants are viable for several years without external intervention. The aquarium is mainly inhabited by tiny shrimps.

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Botanisches Institut
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80638 München, Germany


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