Undeniably Gorgeous Collaborative Flowers - Great "End of the Year Art Project" - done with grade but could do with ANY grade! To be quicker - like as a party activity - this could be done with pre-cut shapes, too.
School science/garden idea: This frame made to look like a flower pot adds visual charm to growing lima beans with kids. Wet a paper towel and put it in a sealed bag with a few beans. Change the wet paper towel every few days.