In general, the pizza garden presents a good way to explore where our food comes from. Kids eat a lot of pizza, but most haven't clue about the historical, nutritional, etc. Be aware that a fungus called ergot infects some grains. Eating ergot infected grain can cause ergotism, which can have mild to severe repercussions ranging from altered behavior to death. Grind the wheat by hand with a grain grinder.
Flowers appear with incredible frequency on gravestones, and they are widely planted in cemeteries.
Read A-Z flower and vegetable children's books. Back to the Latin names - research what they tell us about the growth habits of some of the plants. Compare the leaves and flowers from different plants. Use the paper as the background. A garden like this can be very beautiful, and very educational.