Every Spring, I do a little lesson to celebrate the National Cherry Blossom Festival in Washington D.C. The story about the cherry trees is a nice way to encourage the students to think about friendship and emphasize good deeds. Just research the history of the cherry trees if you are interested in teaching this lesson in your classes. I have a slideshow that I play showing photographs of the cherry trees around the Capital in D.C. while the students are working. I vary this lesson depending on grade level - kinders paint the tree and use fingerprint dots as the blossoms, 1st and 2nd graders paint the tree using the Japanese Sumie technique and paint finger dots in an actual blossom (four dots w/ one in the middle), 3rd and 4th graders paint the trees using the Sumie technique and cut small circles out of pink paper to create their blossoms.
1st Grade example (close-up branch painting)