Edible Gardens are all about teaching kids to grow and cook. On their website you can download a number of free programs, competitions and hot tips for developing your own edible playground. The initiative originated in the UK and is similar to the School Garden Movement here in the U.S.
Here is a couple of samples of some free information from the website:
Part of the sow it grow it set of activities, students grow grass seeds in a tube and measure and trim "green hair" as it grows.
Grow seeds in a jam jar creates a green house like effect to visually watch seeds sprout.
Other activities link.