An old folk belief in rhyme: wash your face in May Day dew from a hawthorn tree and you'll be handsome ever after. A nice way to introduce a real seasonal custom alongside the verse.
From Mother Goose / Nursery Rhymes (traditional). See the whole collection.
The fair maid who, the first of May,
Goes to the fields at break of day,
And washes in dew from the hawthorn-tree,
Will ever after handsome be.
About this rhyme
Recalls the old May-dew custom
This little verse holds on to a real old custom. On May morning, girls would go out early and wash their faces in the dew, especially dew caught on hawthorn blossom, to make themselves handsome. People genuinely did it. Samuel Pepys noted in his diary in the 1660s that his wife went out to gather May dew to wash her face with.
It is a calendar rhyme, not an action one, so it belongs to a single morning. Say it on the first of May, then take the child outside to touch the wet grass and the hedge. You do not have to believe it works. The fun is doing a small thing that people have done on the same morning for hundreds of years.
Public domain. Text from The Real Mother Goose (Blanche Fisher Wright, 1916), via Project Gutenberg. View the source edition