Can all plants live in the sea?

On Monday we began an investigation. We remembered out trip to the seaside and wondered whether all plants could live in the sea, like seaweed. We took two plants. They were the same species - petunias. Lewis chose two of the plants that were nearly identical - the same size, same number of buds, both with no flowers yet. We also made sure we used the same type of pot, the same compost, and we put them in the same place in our classroom. 

The only thing we changed was: we decided to give one plant ordinary water to drink and gave the other one salty water. Can you remember why we made everything else the same?

Here's a picture of the salt being added to the water.

Our scientists tried to give the plants the same amount of water too, as you can see.

The picture above shows what we found when we came into class the next morning (Tuesday). The salt water plant was drooping over while the ordinary water plant was standing up straight and tall.

Our team of scientists kept on watering the plants each day and by Thursday the salt water plant looked like the picture above. The leaves were all shrivelled up and there was some white, powdery stuff (that looked like salt) all round the base of the stems. 

The ordinary water plant looked quite different: just look at the picture below...

We carried on watering the plants each day and by Friday they looked like this:

Can you think of some good adjectives to describe the two plants? What do you think our investigation has taught us? Could all plants live in the sea?