Subject: Do leaves absorb water throught the top or bottom of the leaf?

My 10 year old son is doing a science project. He wants to show if leaves 
absorb water from the top or bottom. I am trying to help his present this. Can 
you help on how to pose the question? our thought was to take two plants, coat 
one with petroleum jelly on the bottom of each leaf, the other the top of each 
leaf. Each day for two weeks he will brush either the top or bottom of the 
leaves with water, then chart the results. Or do you have any other ideas that 
he might try? Directions would be helpful.....thank you

Re: Do leaves absorb water throught the top or bottom of the leaf?