Right after Harvest, You can give the trees another application of Fertilizer similar to our Spring/Summer suggestions. Or, spread about 2 to 5 pounds of compost per tree in a 6" band around the drip line, under the mulch. (Keep away from the Trunk!)
If it's later in the fall: sit back....enjoy the view of the School Orchard, do nothing, think about the pleasures of Dormancy...... Lucky trees!
All that food and stuff from the leaves (starches, carbohydrates, sugars, pigments, water etc. etc.) has been retrieved (sucked back actually) by the trees..... before they actually dropped the leaves. All that food is stored in the trunk and roots. In the Spring, before there can be any energy production from leaves, the "sap" will come rushing up from storage to fuel the whole works. Vermonters will tap off some as "Maple Syrup" for Pancakes, and Southeast Alaskans will tap off "Birch Syrup" for their biscuits. It's sweet 'cause it's loaded with sugars and Energy.
Don't worry there will be plenty to do later, but in the School Orchard more Fertilizer is usually not needed! The exception is:
If you've noticed a deficiency (yellow leaves during mid-summer), post-harvest is a good time to correct the deficiency.
Short of doing a leaf analysis, the Compost application is your best shot at fertilizing and correcting the nutrient deficiency.
Hint: Supermarket Chains in Los Angeles County have their day old and wilted Produce professionally composted. Vons especially has been very happy to donate compost to our School Gardens and Orchards. The Compost is Superb!! It's arranged through the Manager of the neighborhood Market in the School's community. It's likely done by chain Markets throughout the State. Their objective is to sell the Compost to Organic Farmers. A neighborhood manager can donate a load to your School Orchard. Be grateful... and post a sign thanking them.... the school garden and orchard can be a real link between school and community.