Soil Worlds: Self-made root window

Do it yourself

We walk, stand and move on the floor every day without thinking about it. Obviously, everything important happens around us and not below our feet. What should be exciting down there? Actually a lot!

Life rages in the soil and there are lots of creatures crawling and creeping around. You meet a whole community of fungi, plants, animals, bacteria and many other organisms. In a single handful of fertile soil there are more living beings than there are people on earth.


In this experiment you can take a closer look into a secret world and observe the growth of a root that is normally hidden under the surface of the earth. You can record your observations with a flipbook or on video.

Let's go - have fun!

You want to learn more about life underground?

Why do roots have hair? Are earthworms underground giants?
Can the soil help us to protect the climate? And how is soil formed after all?
Below you will find additional information about the hidden soil worlds
and links to information material that we found online on the topic!


  • Suitable for age group: about 6-14 years

  • Especially interesting for: Everyone who enjoys a long-term project and would like to observe and document a change over two to three weeks

  • Preparation time: about 20 min + several weeks
    (watering and observations)


  • You need:

  • Some soil

  • Plant seeds (e.g. radish or cress)

  • An empty jar or bottle with a wide opening

  • A small bowl

  •  Aluminum foil
  •  Scissors
  • A toothpick

  • A rubber band


You can collect the required soil or earth with a small shovel from the garden, from a meadow or from the forest.


Step 1: Get ready

First of all, get all materials ready on your table. Open the jam jar or glass bottle and put the lid aside, since we don't need it.

Step 2: Plant seeds

Fill the jar to approx. ¾ with the soil and moisten the earth slightly. Make sure that the ground is not too wet.
There should be no water at the bottom of the jar.

Now you can take two or three of the seeds and place them directly on the edge of the glass. Mark the spot with a toothpick so that you can find it again later.

Cover the seeds with some soil and keep them slightly moist for the next weeks.


Step 3: Cover the jar

Cut off a piece of the aluminum foil. The piece should be as wide as your glass is high so that it can cover the whole surface. Wrap the strip once around the glass and fix it with the rubber band.


Step 4: Set up the jar

Take a second piece of aluminum foil.
The size does not matter here, because it only serves the stability of the jar. Wrap the foil a little bit and put it into the bowl.

Now carefully tilt the jam jar and place it in the bowl at an angle of about 30°. The side with the protruding toothpick should be inclined downwards
(if the glass does not have a stable stand, it can be stabilized with more aluminum foil).

Almost done! Now just put your bowl in a warm place where it gets a lot of light. A windowsill is ideal for this.


Why does the glass have to be placed at an angle?

Roots always grow straight downwards. So if the jar were to stand normally, we would not be able to see the roots properly. But we trick them! Because the jar is tilted, the root hits the side wall. It cannot grow through the side wall, so it grows down along the wall and we can watch it.

Step 5: Observe

Now you can lean back, relax and observe your root window. If the soil feels dry, you should give your plant some water. Every one or two days, look at what has changed and how the roots have grown.

The first few days:
During the first few days your seeds will absorb moisture from the environment and swell. This will activate them and germination will begin. First the roots will form, then you can see a small stem that breaks through the surface of the earth that has small leaves.

Step 6: Flipbook or Photo documentation

If you want to record your observations, you can draw a flipbook on how the roots change over time.

You need

  • Transparent paper or foil
  • A pen
  • Staples or a stapler
  • Some patience and stamina

And this is how it works

Hold the paper or foil to your glass and draw the roots. Repeat this step regularly so that you have several drawings of different root lengths. You can now staple them together in the correct order, i.e. the first drawing at the top and the last one at the bottom. If you now scroll through the drawings with your finger, you can see the change as if in time-lapse.


Alternatively, you can also take photos with a camera or cell phone and combine them with a computer program (e.g. Kizoa or Animoto) to a short film or slide show. Here you have the possibility to personalize the video with cool effects and transitions.

and Observe!

Learn more!

Not only plant roots grow in the soil. A whole world of animals, fungi and microbes lives here. Soil life is an important part of the ecosystems on our earth. In addition to the living beings, our soils are also full of valuable treasures! Many important salts, minerals, precious metals and also precious stones can be found here.
Surely you have heard that the skeleton of a dinosaur was found in the ground, so fossils are also hidden here. For us humans the soil is also very important. We live on it, use it as a source for various raw materials and grow our food on it.

Exciting facts about life in soil

If you want to dig deeper and can't get enough of the underground worlds, you' ve come to the right place.

Hairy business

The root of your plant is covered with tiny hairs, the so-called root hairs. With the help of these small hairs, the plant has a larger surface area around the root and can better absorb water and nutrients.

Underground Giants

Earthworms are true giants in their habitat! Even though the useful worms may seem small to us humans, they are huge compared to other soil animals: While you could still see springtails and threadworms with the naked eye, you can only observe waterbears or ciliates with a microscope.

Where does soil come from?

To get to the bottom of this question, we need to dig deeper, because at some point we will come across a layer of rock beneath the soil layer. Our soils were formed from this rock through weathering over millions of years. Depending on the original rock, age of the soil and climate, very different soil types can arise, for example brown soil, black soil or podsol. This is a really exciting field of research because physics, chemistry, biology and geology come together here!

Terra preta: Black Gold

Even if a fascinating biodiversity can be found in the rainforest around the Amazon, the soils there are actually not particularly rich in nutrients and therefore not well suited for arable farming. Therefore, researchers were amazed when they found the so-called terra preta: this type of soil was created by the indigenous people of the Amazon basin by mixing in charcoal, dung, compost and potsherds. Terra Preta has similar properties to black soil and is therefore particularly fertile! Research is being carried out on and with Terra preta worldwide.

Soil protection is climate protection

Just as trees, soils can store greenhouse gases, too. They bind a lot of carbon, especially if they contain a lot of humus. Gigantic amounts of greenhouse gases are also stored in moors. Therefore, when buying potting soil, you should make sure that it does not contain peat, because the decomposition of peat damages our moors and is therefore bad for the climate!

Related Links

Created by Kim Schmitz

Naturkundemuseum Bayern
Botanisches Institut
Menzinger Str. 67
80638 München, Germany


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