Bean in a Jar Science Experiment

This germination science investigation is very simple but fascinating. Did you know you can grow a bean in a jar with just a little water? Once the seed has germinated, you can place it in soil for the plant to finish growing.

The jar allows children to see the seeds, roots and shoots easily.

What is germination?

Germination is the sprouting of a seedling from a seed.

Three factors are important for germination.

Water—Seeds need water for germination to occur. When a seed absorbs water, it starts to swell, the outer coat cracks and roots start to grow through.

Oxygen – oxygen is needed for a plant to grow (oxygen is needed for respiration to occur ). Seeds buried too deeply in the soil won’t grow.

Temperature – the temperature can be important ( warm or cold ), depending on the type of seed.

Once a seedling has used all the nutrients from the seed, it then needs to take nutrients from the soil. Once your seed has germinated and grown a little bit, you’ll need to transfer it into a pot of soil.

Light is not needed for germination but is needed for a plant to grow.

Roots grow downwards to anchor the plant in the ground and find nutrients, and shoots grow upwards to find light.

How to grow a bean in a jar

What you need

• A broad bean seed
• Jar
• Kitchen towel or a napkin
• Water

Instructions

• Swirl a small amount of water around the jar.
• Fold your napkin or kitchen roll and place it in the jar ( we also made the kitchen roll very slightly damp).
• Place the bean seed in the jar resting on the napkin.
• Spray some water on the bean every few days.

The bean should start to grow roots after a few days. This is called germination.

We kept one bean in the dark and one in the light. Both seeds germinated and grew into small bean plants. This shows that light is not necessary for germination.

You can see here that the plant grown in the dark is slightly less green than the one grown in the light. We have seen this before when growing cress.

What amazes me the most is that all this can grow from one tiny seed with no additional nutrients other than those contained in the bean.

After a few days in the light, the bean plant kept in the dark was as luscious a green colour as its counterpart.

Bean in a jar instructions

Download the instructions completely free!

More plant science

Little ones will enjoy growing a bean for Jack and the Beanstalk.

Inspiration Laboratories has a lovely plant science experiment growing seeds in different soil types, such as sand and stones.

Playdough to Plato has a gorgeous sprout house!

Another idea is to dissect a plant or try one of our other fun plant science experiments for kids.

Suitable for:

Key Stage 1 Science – Plants

Plants

Identify and describe the basic structure of a variety of common flowering plants, including trees.

Last Updated on March 24, 2025 by Emma Vanstone