The Bean Plant Science Experiment

This easy to set up plant science experiment will give your child insight into what is happening when seeds germinate, how the seedling emerges from the seed, and how the roots grow. The experiment also allows your child to both watch the growth of and care for bean plants.

Materials Needed: You will need the following:

* a large plastic drink bottle (1.25L size is best), preferably with straight sides
* strong scissors
* several strong paper towels
* soil
* bean seeds

Procedure:

Step 1: Cut the top off the 1.25 litre bottle so that it resembles a large drinking glass.

Step 2: Turn the bottle over and punch several holes in the bottom so that excess water can drain out.

Step 4: Fill the space inside the paper towel tube with soil. Sand can also be used if you want less mess, but the soil is better for the plants as it will give them nutrients. Do NOT water the soil at this point. The setup is simple but may require a couple of tries to get right, so be prepared to have to empty the container and start again.

Step 5: Push bean seeds down the side of the bottle so that they are between the plastic and the paper. The seeds need to be in plain view. It is best to push them about one third of the way down the paper. Place a total of four bean seeds evenly around the outside of the paper in this manner, to ensure that at least one will grow properly.

Things to watch out for: Some common pitfalls then setting up this plant science experiment are:
* Ineffective drainage holes from Step 2. Make sure these are open enough to allow excess water to drain away. If not, the water will build up in the container and may drown the bean seeds.
* using weak paper in Step 3. Paper such as toilet paper or tissues is not advised for two reasons. First, it is not strong enough to trap the growing roots against the plastic; the roots will break through the paper into the soil and the value of this plant science experiment is lost. Secondly these papers are thin and so the darkness of the soil makes seeing the growing bean roots difficult to see.
* dirt falling on top of the beans as they are pushed in during Step 5. This will obscure your child's view of the bean's growth.

A Possible Extension:

An interesting extension is to transplant the bean plants to the garden so you child can continue to watch their growth.

You can also grow the plants until they have produced bean pods of their own. If you allow these to remain on the plant until they are fully grown and then dried out, you can repeat the experiment in order to demonstrate the life cycle of the plant.