There are 7 layers to a proper food forest:
1. Canopy - large fruit & nut trees
2. Understory - Dwarf fruit trees
3. Shrubs - currants & berries
4. Herbaceous - herbs, perennials and self seeding annuals
5. Rhizosphere - root crops
6. Ground cover - strawberries, squash, clover
7. Vertical - vines