The journey of planting a potato. link has info on how to garden and what to plant with lots of pictures. Garden with your kids - they will ...
Soil solarization to reduce pests and weeds in summer vegetable garden.
A simple demonstration for kids to learn how a leaf gets water from a tree.
Use the book "Only One You". This would be really cool as a school-wide project!
Google Image Result for http://kaboom.org/docs/images/blog/Schoolyard4.jpg
Deephaven Elementary School / Interactive Outdoor Classroom