Maine has a Kids Can Grow gardening class through the extension service. It is for kids 7-12. They have 6 classes where they are taught about gardening. Additionally volunteer master gardeners will visit the house to work with them on their own garden. The program provides a 3x5 raised bed and all the seeds soil ammendments etc to start their own garden. All this for $25. It is a neat program and if you have kids you might want to see if your state offers something similar..