Bill Palmisano is exactly right in Restore Wilderness to Hidden Valley School Property. Growing food should be on all school campuses, not at some far away place.
Young people of all ages can be encouraged to work in the vegetable/herb garden as part of their school day, at lunch time, after school, or as a class assignment.
Supervision would be needed but much valuable learning will occur — reading, math, science, and immediate useful end to the learning.