Hi Allison, This may not help- but we do have a state policy here in DC that funds the school garden program out of the state education office. Here's the legislation https://code.dccouncil.us/dc/council/code/sections/38-821.02.html
. I'm happy to discuss more with you if you are interested in the details.
Off the top of my head, Tucson Unified School District, Berkley, Cambridge, Oakland, and Chicago Public Schools probably each have a policy, happy to put you in touch with them if you are interested.
Most schools in DC incorporate school garden policies into the local wellness policy. Hope this helps!