If you have space in the vicinity of the school or in the school garden, set up a herb patch with your pupils. Choose a few herbs and plant them in the patch. Label the herbs and describe their use in a household or pharmacy with your pupils and place the descriptions on a suitable place in the school.
If you do not have a suitable space, plant the herbs only in the flowerpots or boxes on the windowsill, with pupils observe how the herbs grow, when they bloom, what colour they have, etc.