6. Acknowledge volunteers-- We all appreciate a thank you. Find ways to acknowledge the efforts of your volunteers through certificates, social events, newsletters, school assemblies, etc. One Ohio school has students raise plants to give to volunteers as a small thank you gift.
This is a lovely practical list. I'd like to add to this...when parents enrol their child into school, get them to complete an optional skills and interests sheet where they list their profession, hobbies, skills and interests. This can go beyond simply outdoor activities but extend into any other project work. In my experience, people often like to be asked directly, so if one knows a person with a skill who could assist the school then a direct approach really works.
A great example of this is one this fence blog. The fishing net was made by children with the help of a local fisherman. It's been used as an outdoor display. One year later, it's still up and running - in fact at the moment it's full of recycled spiders!
I've also involved older children in maintenance programmes over the summer. For example, from the school fund we paid children pocket money to come and water the plants on a twice weekly basis.
Hope this adds to any discussion - I'd love to hear more suggestions from others.
The fence art is wonderful! Every school has the "ugly chain link fence" which can become a marvelous gallery upon which to display student work. Thanks for sharing.