The soil will settle in layers. I offered the extension of doing a drawing of what we can see in the layers but no-one has taken me up on that yet - but the jar is still sitting on the bench so I wouldn't be surprised if they want to later.
This lesson idea was from this sample page (Plant Needs) on the New Child Montessori Curriculum website.
I've decided that I am definitely going to buy the Guides! Having trialed them for the past little while (using the sample pages) I think that they're just so good & Gini (who created them) has been so helpful in answering my questions via email :)
Now (to complement the Guides) I just need to place my first Montessori materials order... eeeek! It's thrilling but scary too. More to come on this topic, for sure!! :)