Dear Gwenne, Here are 2 sources that might give you some leads...
1)Growing Gardens--"Creating gardens with volunteers for fresh food, learning, exercise & friendship where the need is greatest", a community partnership that starts lots of private community gardens,especially among low-income & organized groups(schools,nursing homes,apartment complexes,neighborhoods,etc.). Program coordinator---Hannah Burton(phgp@teleport.com),mail-2003 NE 42nd Ave#3, Portland,Or 97213,503-284-8420-phone,503-284-5355-fax. They have recently gone into winter "hibernation", so keep trying...
2)The Portland, Oregon School District has had a specialized high school curriculum program for ~25 yrs that combined vocational & academic horticultural tracks into 4 yr actual experience. They also had jr high level intro courses that funneled interested students into the high school. I think the current name of this program is "Green Thumb". They have been subject to lots of research studies & might be able to help you with your questions...
Best wishes & good luck!!