What makes seeds grow well?

One of the things we did right at the start of this unit of inquiry, was think together about what plants need to grow well; what makes seeds grow into healthy plants?  The list we came up with included these things:

• water
• sunlight
• soil

But of course we couldn't just leave it at that; so we decided we would test whether cress seeds need these things to grow well.

We worked with a partner.  We decided with our partner what we would find out about; whether cress seeds need water, or sunlight or soil. 

We asked a question; either

Do cress seeds need water to grow well?

Do cress seeds need sunlight to grow well?

      or

Do cress seeds need soil to grow well?

We showed our thinking:

I think that cress seeds need/do not need water to grow well

I think that cress seeds need/do not need sunlight to grow well

I think that cress seeds need/do not need soil to grow well

Then we set up our investigation.  Each table had cups, soil, cress seeds , water, pink fluff.  We had to choose what we would use.

Do cress seeds need water to grow well?

• We put soil into two cups
• We put cress seeds into two cups
• We put water into one cup but no water in the other
• We put the two cups in a sunny place

Do cress seeds need sunlight to grow well?

• We put soil into two cups
• We put cress seeds into two cups
• We put water into two cups
• We put one cup in a sunny place and one in the dark

Do cress seeds need soil to grow well?

• We put soil into one cup and pink fluff into the other cup
• We put cress seeds into two cups
• We put water into two cups
• We put the two cups in a sunny place

Then we waited for a few days.....and this is what we saw.

Do cress seeds need water to grow well?

Do cress seeds need sunlight to grow well?

Do cress seeds need soil to grow well?

What can you say about what we found out?  Do cress seeds need water to grow well?  Do cress seeds need sunlight to grow well?  Do cress seeds need soil to grow well?

Were you surprised by anything?  What do you notice about the cress seeds that grew in the dark?  Why do you think those plants look the way they do?  Do you think what we found out is the same for all seeds?

Oh and here's something else to think about.  What do you think would happen if we planted seeds in pink fluff but put them in the dark?  Would they grow well?

And what about if we planted seeds in pink fluff but gave them no water?  Would they grow at all?

Why not try it yourself and find out if you are right?