Avocado!

I'm not sure what the conditions have to be in order for an avocado tree to grow, but I'm pretty sure Idaho isn't listed in those states. I love avocado. And my boys love guacomole if you don't tell them its avocado. :) My boys also love a good science experiment.

Take 3 toothpicks and stick them about 1/2 in into the avocado pit

Put it in a cup or jar and fill the cup or jar up with water enough that it covers the bottom chuck of the pit. I should mention, you want the part with the "belly button" to be in the water. Put the pit in a window that will get the most light.

It will take a few weeks for leaves to pop out, but I think they will really enjoy watching it make progress with the roots.