Bring home from a walk seeds of ash, maple, Linden, any tough stems, flowers. All of this can make a very interesting bunch.
Take a small piece of clay and roll it into a ball - this will be the core of the flower. The seeds of ash or maple pointed tips into the clay to make a flower like a Daisy, clover or some other. place the flowers on the stems. The bouquet put in a vase that your child made from bottles of colored paper.